270 BULLETIN OF THE 



I have no doubt that the shell about to be described, and most if not all 

 of Deshayes's Mcsostoma species, belong to the family Trichotropidce, though 

 hitherto placed elsewhere. 



Mesostoma migrans Dall. 



Plate XXIX. Fig. 8. 

 Trichotropis migrans Dall, Bull. M. C. Z., IX. p. 71, 1881. 



Habitat. Station 36, near Havana, 80 fins., Sigsbee. 



So far only the original specimen has turned up, and that does not retain its 

 epidermis. 



Genus? DOLOPHAXES Gabb. 



Dolophanes Gabb, Proc. Acad. Nat. Sci. Phil., 1872, p. 273 ; Trans. Am. Phil. Soc, 

 XV., Geol. St. Domingo, p. 234, 1873. 



This genus was referred to the Struthiolariidce by its author, a reference 

 which has been questioned by all those who have had occasion to refer to it 

 since. The occurrence of a specimen in the Blake dredgings, which, if not 

 identical with Gabb's type is evidently closely related to it, enables me to 

 state that its proper position is probably in this family. Unhappily the oper- 

 culum and soft parts are wanting, so that I cannot confirm my opinion by ref- 

 erence to the details of its organization. I am inclined to believe that another 

 form, also represented in the Blake dredgings, is a representative of a shell 

 described as a Melanopsis by Guppy, which Gabb himself suspected to be 

 closely related to his Dolophanes melanioides. All these specimens are fresh, 

 but the slight traces of epidermis which they retain are not of the character of 

 the northern species of Trichotropis. Their variations are such that I am led 

 to believe all three may be merely mutations of one specific form. If this be 

 confirmed, the specific name of cupula, given by Guppy, is the oldest. Whether 

 the differences are sufficient to constitute for Dolophanes a rank higher than 

 that of a mere section of the genus Trichotropis, a more thorough knowledge of 

 its characters is needed to determine. 



Dolophanes (melanoides Gabb var.?) Gabbi Dall. 



Plate XXIX. Fig. 7. 



? Dolophanes melanoides Gabb, Proc. Phil. Acad. Sci. 1872, p. 273, pi. xi. fig. 7 ; Geol. 

 St. Domingo, p. 235, 1873. 



Shell small, thin, white, (epidermis lost,) with rather acute turrited spire 

 and eight whorls; nucleus smooth, polished, somewhat inflated and turned a 

 little to one side; second turn also smooth, all the others strongly sculptured; 



