Vol. 62.] BRACHIOPOD HOM(EOMOEPHY. 447 



take one of Pictet's figures as the neotype. The battle-axe shape is 

 suggested in Colonna's figure ; it is shown to perfection in Pictet's 

 pi. xxxi, fig. 1. This character and the practically straight side- 

 margin separate the species from Antinomia ; but I do not feel 

 certain that this species really belongs to Pygope — that is, that it 

 is a development of Pygope deltoidea. 



Subperforate. 



Pygope (?) solidescens, nom. nov. (PI. XLI, fig. 15.) 



1870. Terebratula triangulus ; Zeuschner [39] {non Valenciennes) pi. vii, 

 figs. 5-7. 



It is necessary to name this species for the sake of reference : 

 the name chosen signifies the closing-up of a wound, which the 

 obsolescence of the perforation seems to suggest. 



Concerning the specimen which he figures, Zeuschner says : — 



' L. von Buch has correctly united T. triangulus with T. diphya : interesting 

 evidence for that opinion is found in the specimen from Kijow. The perforate 

 [ventral] valve is not entirely smooth, as is the case with the ordinary T. tri- 

 angulus, but, in the upper half, is seen the commencement of a hole, and from 

 it to the anterior end runs a small sinus [sulcus]. This hole has an appearance 

 like that shown by T. dilataia ; Pictet, Mel. Pal. pi. xxxii, fig. 'da; but it does 

 not pierce both valves, and is barely 4 mm. deep. In the imperforate [dorsal] 

 valve there is, in the place mentioned, only an insignificant deepening 

 surrounded by several small depressions.' (Op. cit. p. 270.) 



An important point to be noticed about Zeuschner's specimen is 

 that its anterior end is not swallow-tailed, as is the case with the 

 Antinomia dilatata-angusta series : instead it projects forward in half- 

 moonshape. ]N"ow, one would certainly expect any specimen connecting 

 the perforate and imperforate stages of either Antinomia or Pygope 

 to show a swallow-tailed anterior end — some trace of the manner in 

 which the two lobes fused. One would have expected this specimen 

 of Zeuschner's to show an anterior notch, quite as much as a trace 

 of the perforation. 



The horizon from which this specimen of Zeuschner's came is 

 important. He says that it was found on the southern slopes of 

 the Tatra, in the village of Kijow in the Zips. 



According to Pictet [29] p. 809, there are at the Tatra, at least, 

 strata from about Portlandian to Neocomian ; and Zeuschner seems 

 to suggest that this specimen came from the same formation as the 

 Klippenkalk [Portlandian] which yields the ordinary Terebratula 

 triangulus [Antinomia pileus], with which he compares his specimen. 

 Seeing, however, that T. erbaensis was once confounded with 

 T. diphya. and supposed to come from the same formation, the matrix 

 being so similar, but was afterwards discovered to be an Upper-Lias 

 shell, it may be suggested that with Zeuschner's specimen there has 

 possibly been a similar error. But it would be most remarkable if, 

 in a series which has as yet yielded no examples of the perforate 

 stage, this subperforate form were found ; while, in the diphyoids, 



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