116 AMERICAN JOURNAL 



McCoy's type ; it is- also one of the types of Dalman's trouble- 

 some genus RhyncJiora and is placed by Gray in the subgenus 

 Lyra (Cumb. 1816). 



Dalman's first species of Delthyris was D. elevatus, a true 

 Spirifer of the Silurian age. Menke quotes the name Delthyris 

 with its proper synonyms and gives Terehratula dorsata and T. 

 caput serpentis as examples. But, since neither of these species 

 was included in Dalman's list of Delthyrides, the reference of 

 Menke could not be construed so as to allow of the application 

 of Delthyris as a generic name to either of the two species he 

 cites. Hence Delthyj'is, Menke, must stand as a synonym of 

 Terehratellciy while Delthyris^ Dalman, bears the same relation 

 to Spirifer. 



Fig. 13. Terebratella dorsa/a, lm?mal valve, showing apophyses. 



Type Terebratella dorsata, Lam. 



Anomia striata viageUanica, Chemn. Conch. Cab. v. viii, p. 



101, pi. 78, fig. 710, 711. 

 Terehratula 3Iagellanioa, Rve., Conch. Ic, pi. v, fig. 21, a, b, 



c, d. J. de Conchyl. 1861, p. 127. 

 Terehratula dorsata, Lara., An. Sans. Vert. v. vii, 1819, p. 



331. 

 Anomia dorsata, Gmel. 1788, S. N. 3348. 

 Terehratula Chilensis, Brod., P. Z. S. 1836, 134. 

 Terehratella Soiverhyi, King, Zool. Journ. v, p. 338. 

 Terehratula hilohata et pecdnata, Blainv., Teste Rev. Journ. 



de Conchy. 1861, p. 127. 

 Delthyris dorsata, Mke., Syn. Ed. 2, 1830, p. 96. 



Ifah. Coasts of Chili southward to the Straits of Magellan. 

 Smithsonian Cab. 17822, 17815. As Chemnitz was not a 

 binomial writer, his name cannot be retained. 



From the specimens and descriptions at hand I can only 

 agree with Reeve in uniting the above synonyms under the name 

 of dorsata. Of six specimens received from Mus. Cuming, 

 under this name, two were Terehratellas ; the remainder beloncred 

 to the genus Magas. T. transversa, Sby., probably belongs to 

 this species. 



