fh. I. Pocock—Carboniferous Arachnida. 505 
There are considerable differences between Sowerby’s figure and 
the photograph of the type-specimen reproduced in the Palaontologia 
aniversalis (sér. 11, fasc. 1, No. 92a), but it should be mentioned that 
Sowerby’s figure, besides being reversed (as usual) and somewhat 
restored, represents the fossil without the natural internal cast of the 
body-chamber (which, as Sowerby himself observed, is separated from 
the rest of the shell), whilst in the photograph this portion of the 
fossil has been placed in its natural position. 
VII.—Nores on tort Morrnotocy anp Grnertc NomMENCLATURE OF 
SoME CARBONIFEROUS ARACHNIDA. 
By R. I. Pocock, F.L.8., F.Z.S. 
1. On ANTHRAQOMARTUS AND PROMYGALE. 
N his monograph of Paleozoic Arachnida published in 1904, 
Dr. Fritsch divides the order Araneze into two suborders—the 
Arthrarachne, Haase, containing the Arthrolycoside, and the 
Pleuraranes, Fritsch, containing the Hemiphrynide (Hemiphrynus) 
and the Promygalide (Promygale). 
Haase, Beecher, and others, whom Fritsch follows, were no doubt 
right in referring Arthrolycosa and allied genera to the order Aranee, 
but the Pleuraraneze are in my opinion nothing but Anthracomarti, 
the genus Promygale itself being synonymous with Anthracomartus. 
The form of the carapace and structure of the appendages are the same 
in the two. The constriction between the prosoma and opisthosoma 
occurs in both. The segmentation of the opisthosoma is similar in the 
two, even in the presence of a longitudinal sulcus dividing the pleural 
laminze into an external and an internal moiety, and in the angulation 
of the posterior border of the posterior sternal plates. 
Certain discrepancies in the figures published by Fritsch inevitably 
rouse a feeling of scepticism on the score of the accuracy of the 
restorations they represent. In Promygale bohemica (fig. 20) there are 
eight dorsal plates; each of the anterior seven is furnished with 
a divided pleural lamina, the posterior border of the eighth being 
produced in the middle line to form an unpaired plate. But in 
fig. 21, showing the ventral side, the last-mentioned plate is paired 
by a longitudinal sulcus. In P. elegans (fig. 26a, dorsal view), on the 
other hand, there are only seven dorsal plates. On the seventh the 
inner moieties of the pleural lamin are not shown, but on each side of 
the opisthosoma ten sclerites represent the outer moieties of these 
lamine. It is impossible to refer these with any certainty to their 
appropriate somites, and impossible to say which of the original seven 
pleural lamine have been subdivided to add to the number. A similar 
augmentation is shown in fig. 23, representing P. rotundata. This 
feature, if existent, should constitute a generic difference between 
P. bohemica on the one hand and P. elegans and P. rotundata on the 
other; but the drawings of the actual specimens of P. elegans (pl. xv, 
fig. 2) and of P. rotundata (text-fig. 24, p. 20) afford, so far as I can 
see, no support to the view that the pleural lamine are numerically 
in excess of the somites. On the contrary, there appears to be 
complete agreement between them in this particular. 
