PALAEONTOLOGY OF NEW YORK. 



Genus AULONOTRETA, Kutorga. 1848. 



1848. Aulonotreta, Kctoroa. Debei- die Siphonof letaefe : Verhamll. der Russ.-kais. Mineral. Gesellsch. 



zu St. Petersb. Jalirg. 1847, p. 278, pi. vii, figs. 10, 11. 

 1869. Acrltix, Volbokth. Ueber Schmidtia, iind Acritis, idem., 2te Sei'. Bd. iv, p. 217. pi. xvii, figs. 7-9. 



The name Aulonotreta was proposed by Kutorga to take the place of 

 Obolus, Eichwald, as he deemed the latter an inappropriate name. The first type- 

 species under the description is A. polita, Kutorga, which "umfasst folgende, von 

 Professor Eichwald, aufgestellte Arten : Obolus ApolUnis, 0. Siluricus und ingricus, 

 deren untersclieidende Merkmale weder mit Worten, noch mit Zeichnungen 

 gegeben werden konnen."* As 0. ApoUinis is, however, generally recognized 

 as a well-defined species, Kutorga's first type and his genus, as far as it rests 

 on this type, became synonyms for Obolus. The second type, Aulonotreta sculpta, 

 Kutorga, is a synonym for the Obolus 

 antiquissimus, Eichwald,| and this species ^^ _ -N^ 



was taken by Volborth as the type of \ ^ 



his genus Acrh is.t The species is very \ ' ^ ^ f 

 imperfectly known. Volborth's figures \-- ^-^^ \j: 



indicate a close agreement with Obolus 



•x c Till i. c Acritis antiquissima. 



in general lorm, and the characters ot ^^3,. v\,lboeth. 



At T 1 rill • 1 i_ • Fig. 35. Interior ol" pedicle-valve. 



the cardinal area. Ihe incomplete m- k.g.^w. i.uenor of irachiai vaue. 



teriors figured show in the pedicle-valve, a broad, subquadrate median scar, 

 crossed on its posterior portion by a transverse band connecting what appear 

 to be cardinal scars. In the lirachial valve are two subcircular scars in the 

 median region just within the posterior margin. In the event of this form 

 proving distinct iVom Obolus, the laws of priority require that it shall bear 

 the name Aulonotreta, for which Acritis will then be a synonym. 



* Pp. 281, 282. 



t Ui-welt RiissL, 1843, p. 142, pi. iv, fig. 1 a, b, c. 



X Lov. cit. 



