CONTRIBUTIONS TO PALEONTOLOGY. 303 



"In that paper I described two species with closed beaks, A. clara and A. 

 ■maia, which uo doubt beloug to the genus. The others, with perforated beaks, 

 I marked doubtful, thus: A. (?) scitula. Hall; A. (?) clusia, n. s. ; A. (?) 

 unisulcata, Conrad ; A. (?) rostrala, Hall ; A. (?) chloe, n. s." 



The paragraph following this does not seem to be relevant to the subject ; 

 and the remarks about Mr. Hall having proposed a genus Meristella 

 have been so often before the public in some form that it is scarcely worth 

 while to occupy space by citing what is said in this place. I may, how- 

 ever, briefly allude to a former statement of Mr. Billings, in the Canadian 

 Journal, 1860, that I had proposed the name Meristella for those " shells 

 which have Athyris tumida for the type." This is quite incorrect, so far 

 as I am aware. The generic name was proposed in 1860, and used by 

 me in the descriptions of the plates of Vol. iii, Pakeontohgy of Neiv York ; 

 and under the generic description, published in 1861, I gave examples 

 M. Icevis, 31. bella and M. arcuata of the Lower Helderberg group, besides 

 others. I cited M. tumida as belonging to the genus, simply from a gen- 

 eral similarity of external form, and similarity of muscular impression 

 in the ventral valve. Of " the others with perforated beaks," etc., cited 

 above, the ^. (?) scihda has no more a perforated beak than has A. tumida. 

 Nor does Mr. Billings mention this fact in his original notice of the 

 species in the Canadian Journal ; and in the original descrij)tion of A. (?) 

 clusia, Mr. Billings says " beak of ventral valve erect, apjjarently a little 

 incurved at the tip." Of A. (?) unisidcata, Mr. B. says " the beak is 

 incurved over the umbo of the dorsal valve, but its tip not quite in 

 contact with the umbo of the dorsal shell." The figures of this species 

 by Mr. Billings do not show a perforation in the ventral beak, nor is it 

 more conspicuously perforate than A. tumida. The A. (?) rostrata has a 

 perforation, and is a Terebratula. A. (?) chloe has a perforation in the 

 apex, and belongs to the Genus Trematospira = T. hirsuta, Hall, having 

 since been placed under Retzia by Mr. Billings. Mr. B. afterwards pro- 

 posed a Genus Charionella, under which he has placed the A. (l)scitula, 

 A. (?) rostrata, and others, giving, as I have said before, an impossible 

 hinge-structure. 



We will merely give a moment to the two species which Mr. B. says 

 "no doubt belong to the Genus Athyris," quoted above. A. clara is the 

 Atrypa nasuta of Conrad, of which I have specimens from New York and 

 Canada; and typical forms, from the original locality cited by Conrad, 

 are figured in Vol. iv of the Palceontology of New York. The beak of the 

 ventral valve is often apparently imperforate from being closely incurved 



