40 SIXTEENTH REPORT ON THE CABINET OP NAT. HISTORY. 



" The species of this genus are more elongate than Merista and Me- 

 BIStella; and those now known are less distinctly marked by mesial fold 

 and sinus, while the beak is more attenuate, often a little flattened, and 

 rarely so closely incurved as in the genera cited. The punctate structure of 

 the shell is a distinguishing feature." 



In the Fifteenth Report on the State Cabinet, I gave (at page 

 161 fiSS], Plate 3) some illustrations of the muscular imprints, 

 dental lamellae, etc., with figures of a single additional species 

 from 4he Lower Helderberg group.* 



* In the Canadian Naturalist and Geologist for October 1862, we find the following 

 exposition of the relations of the Genus Cryptonella: 



'* Tlie Genus Cryptonella, illustrated on Plate 3, p. 133, is precisely identical with Cha- 

 RiONELLA, described by me in the Canadian Journal of March 1861, p. 148, and illustrated 

 in the May number, pp. 273, 274. It includes the species described by Professor Hall in the 

 Thirteenth Report under the names of Meristella haskinsi, M. barrisi, M. doris, Terebra- 

 tula lincklanif T.rectiroslra, T. lens a,nd T. planostria [T. planirostr a]. Besides these, 

 the Atrypa scitula of the New-York Reports, C circc, and apparently a number of European 

 species, belong to it. Cryptonella was first published in July or August 1861, three or four 

 months after the learned author became acc[uainted with its characters through the study of my 

 papers." 



The following is the description of the Genus Charionella, copied from the Cana- 

 dian Journal (March 1861), No. xxxii, p. 148: 



Genus Charionella. '^ Since the foregoing article on Devonian fossils was written, I have 

 ascertained the generic characters of the so-called Atrypa or Athyris scitula. It has internal 

 spires with their apices directed outwards, as in Athyris and Spirigera ; but the dorsal hinge 

 plate has its anterior margin, and a large portion along the middle, anchylosed to the bottom of 

 the valve. In another congeneric species, the middle portion of the same plate is obsolete ; there 

 remaining only two small, thin, nearly vertical septa (socket plates), one on each side of the 

 cavity of the umbo. The perforation in the beak of the ventral valve is bounded on the lower 

 side by a deltidium of either one or two pieces, or by a portion of the shell. The mesial septum 

 in the dorsal valve is either rudimentary or entirely absent. 



^'The several species of this group, at present known to me, resemble Athyris, but are not 

 so convex, and are besides more elongate-ovate, or approaching to Terebratula in general 

 form. I shall give further details and some figures in the next number of the Journal. 



" The genus is only proposed as a subgenus, to be rfetained in case Athyris is divided." 



In the Canadian Journal. No. xxxiii, p. 273, we have '^Charionella circe, n.s." 

 (referring to the illustrations) . " The first figure exhibits a specimen with the dorsal 

 valve partly removed, showing the internal spires. The other two figures are a side 

 and ventral view of another specimen." 



*' By treating partially silicifled specimens of this genus with acids, I have ascertained that 

 the structure of the hinge plate differs from that of Spirigera in being either obsolete along 

 the middle, or anchylosed to the bottom of the valve. In Athyris (=Meristell a. Hall) , there 

 is a well developed hinge plate, supported beneath by a strong mesial septum which extends 

 sometimes nearly to the front of the valve. In Charionella there is either no mesial septum, 

 or one that is merely rudimentary. In one specimen there is a remarkable partition, which runs 

 obliquely from near the beak to the margin near the front. It completely divides the internal 

 cavity into two parts. This I believe to be not a mesial septum, but a temporary wall formed by 

 disease ; because both spires are crowded into the smaller of the two cavities, the larger 

 being empty." 



The Genus Charionella, therefore, clearly belongs to the Spiriferid^; and the 

 typical species cited are in part those originally placed by me under the Genus Meri- 



