Finally we must consider the specimen described1 as

Euphoberia woodwardi, Baldwin. (Pl. IX, Fig. 4.) This example has been kindly lent to us by Mr. H. Howard, of Rochdale, to whom it belongs. The dimensions are those given by Baldwin. The specimen consists of an impression of the head and a cast of some thirty-eight segments of the trunk. In all important characters the structure of the tergites agrees with that of the two preceding specimens. Part of a ramifying series of small fractures of the dorsal surface, just behind the middle of the specimen, is interpreted by Baldwin as a bifurcating spine. We can find no support for this suggestion. The granulated surface of the tergites is exhibited in some places. Owing to the decortication of the dorsal surface, the spiracles, leg-bases, and duplicated pleurites are again visible, and all these agree with the description already given of the same features in the two preceding examples.

As a result of the re-examination of the material before us, we conclude that these millipedes can no longer be retained in that systematic position to which they have been assigned, and as a step in the right direction, we feel justified in establishing the following genus for their reception :

PALEOSOMA, gen. nov.

Segments numerous (more than thirty-eight), trunk parallelsided, narrowing anteriorly and posteriorly, flattened dorsally with lateral expansions, the dorsal surface furnished with a row of lateral spines on either side, head approximately the same width as the anterior body segments, sternites large, two pleura to each tergite; of the tergites the prozonites are short, hardly visible from the dorsal surface, and the metazonites are large, about eight times as wide as long, divided by a well-marked transverse groove into a smaller anterior and a larger posterior portion, each lateral spine provided

with a tubercular base.

Genotype: Palæosoma giganteum (Baldwin), char. emend. BradeBirks et Jackson.

The two following species fall into this genus:—

1. Palæosoma giganteum (Baldwin), char. emend. infra. (Textfig. 1-2; Pl. IX, Fig. 1.)

SYN.: Acantherpestes giganteus, Baldwin, GEOL. MAG., 1911, p. 76. Length of the last seven segments, 45 mm.; breadth of parallel-sided segments, including lateral expansions, 44 mm.; head unknown, prozonites smooth, metazonites only slightly convex from side to side, finely granulated, divided by the transverse groove into an anterior third and a posterior twothirds, the groove deep near the median line, becoming shallow laterally, to disappear before reaching the lateral borders; lateral expansions prominent, externally foliaceous, and backwardly directed; the spine-base situated the width of the metazonite from its lateral border and equidistant from its anterior and posterior limits (except towards the posterior end of the body (8 segments), where the spines appear to be nearer the posterior border); anal segment small, the posterior end of the body obtuse.

Type: L 9941 and L 9942, Man. Mus.

1 Baldwin, op. cit., 1911, p. 78, Pl. IV, Fig. 2.

2. Palæosoma robustum (Baldwin), char. emend. infra. (Textfig. 3; Pl. IX, Fig. 2-4.)

SYN.: Euphoberia robusta, Baldwin, GEOL. MAG., 1911, pp. 77-8. E. armigera, Meek & Worthen, Baldwin, ibid., p. 77.

E. woodwardi, Baldwin, ibid., pp. 78-9.

Not SYN.: Euphoberia armigera, Meek & Worthen.

Length of anterior seven segments, 22 mm.; breadth of parallel-sided segment (19th from head) 14 mm.; head rounded; eyes present, ocelli in a group, antennæ closely adjacent to the eyes; prozonites smooth, metazonites slightly convex from side to side, divided by transverse groove into an anterior third and a posterior two-thirds, the groove deep near the median line, becoming shallow laterally, disappearing just before reaching the lateral border; lateral expansions narrow and backwardly directed; spine-bases as in preceding species.

Type: L 9943, Man. Mus.

We have made no attempt in the above study to indicate the systematic position of our new genus, but it is our intention to do so in a later paper, which will deal at some length with the classification of certain fossil forms.

EXPLANATION OF PLATE IX.

FIG. 1.-Palæosoma giganteum (Baldwin sp.). Genoholotype × 0.79. Cast of posterior end of the body (L 9941, Manchester Museum).

2.-P. robustum (Baldwin sp.). × 1.36. Impression of some fourteen posterior segments (L 9944, Manchester Museum), showing tergites, pleurites, and walking legs.

3.-P. robustum (Baldwin sp.). Holotype x 1.5. Cast of anterior end of the trunk (L 9943, Manchester Museum).

4.-P. robustum (Baldwin sp.). × 0.76. Impression of the head and cast of some thirty-eight body segments. (In collection of H. Howard, Rochdale.)

IV. -BRACHIOPOD NOMENCLATURE: CLAVIGERA, HECTORIA,
RASTELLIGERA, AND PSIOIDEA.

By J. ALLAN THOMSON, M.A., D.Sc., F.G.S., Director of the Dominion
Museum, Wellington, New Zealand.

IN

N dissenting from Dr. C. T. Trechmann's procedure in rejecting the name of Clavigera for certain New Zealand Mesozoic Spirigerids and proposing the new name of Hectoria instead, I would like first to express the appreciation of New Zealand geologists for the painstaking work of Dr. Trechmann on the Trias of New Zealand.1

The reasons for his rejection of Clavigera are thus stated: 2 "Clavigera represents a group of specialized bisulcate Spirigerids the affinities of which are discussed later on. I have considered it advisable to rename this group, and have called it Hectoria. Hector's description was published without any illustrations, and his subgeneric name closely resembles that of Claviger given to a group of the Melanias."

The close resemblance between the names of Claviger and Clarigera 1 C. T. Trechmann, "The Trias of New Zealand": Quart. Journ. Geol. Soc., vol. lxxiii, pp. 165-246, 1918.

2 Loc. cit., p. 216.

does not necessitate the abandonment of the latter name. Buckman' discusses an analogous case in Brachiopods in these words: "On the ground that Cryptopora was pre-occupied by Cryptoporus, and Atretia by Atretium, Fischer and Oehlert proposed and used the name Neatretia. But though in the case of trivial names cryptoporus and cryptopora would have to be regarded as synonyms, because the termination must be governed by that of the generic name, in the case of the generic name itself there appears to be no necessity to make any change of termination; so that Cryptopora and Cryptoporus as generic terms ought to be quite distinct enough. It is true that such changes of generic termination were commonly made at one time; but such alterations are now discarded in favour of the original selection." Unless, then, Clavigera was accidentally or intentionally employed as a substitute for Claviger (in which usage it would be a synonym of Claviger), prior to the validation of the name by myself for the Brachiopods under question, the name must stand for the latter group, and Hectoria becomes a synonym.

As originally proposed by Hector in 1878, Clavigera was a genus calebs, that is, it was a genus without any species. Hector partly remedied this omission in 1886,3 when he figured two species, but he omitted to name them. In 1913' I discussed the genus and published plates which had been prepared and printed by Hector many years before, and gave names believed to be manuscript names of Hector to four species, viz. Clavigera bisulcata, C. cuneiformis, C. gracilis, C. tumida. Although my intention was to give credit to Hector, the responsibility rests with myself, and according to the opinions published by the International Commission on Zoological Nomenclature responsibility takes precedence over credit in publishing new names. In the publication referred to I did not select a genotype, nor has Trechmann designed a genotype for Hectoria. These omissions I now rectify as follows: Clavigera, Thomson, 1913; genolectotype. Clarigera, bisulcata, Thomson. Synonym Hectoria, Trechmann, 1918; genolectotype Hectoria cuneiformis, Trechmann Clavigera cuneiformis, Thomson.

Hectoria tumida Trechmann is a synonym of Clavigera tumida Thomson, and Hectoria bisulcata Trechmann of Clavigera bisulcata Thomson. Should any subsequent author consider that Clarigera cuneiformis and C. bisulcata are not congeneric, Hectoria may stand for the former. C. bisulcata is Triassic and C. cuneiformis Jurassic.

Rastelligera equally with Clavigera was validated by me in 1913, and the sole species therefore becomes the genotype, viz. Rastelligera elongata, Thomson, of which Spiriferina diomedea, Trechmann, appears 1 S. S. Buckman, "Antarctic Fossil Brachiopoda collected by the Swedish South Polar Expedition": Wiss. Ergebn. Schwed. Südpolar-Exped., 1901-3, Bd. iii, Lief. vii, p. 20, footnote, 1910.

2 J. Hector,

On the Fossil Brachiopoda of New Zealand": Trans. N.Z. Inst., vol. xi, pp. 537-9, 1878.

3 J. Hector, Detailed Catalogue and Guide to the Geological Department's Exhibits at the Indian and Colonial Exhibition, and outline of the Geology of New Zealand, Wellington, 1886, fig. 40, Nos. 2, 3.

4 J. A. Thomson, Materials for the Paleontology of New Zealand": Pal. Bull., No. 1, Geol. Surv. N.Z., 1913, p. 49-50, pl. i.