308 AMERICAN JOURNAL 



fasciatus, but, on the whole, the nearest alliance of the species 

 seems to me to be with B. poecilus, d'Orb. I think that the 

 shell described by me as variety imperfectus may be referred to 

 this species, rather than to B multifasciatus or Vincentinus. 

 Another form of B. aureolus occurs in Tobago, specimens hav- 

 ing been kindly furnished me by Governor Rawson, C. B. This 

 variety (which I propose to call Bawsoni) is exceedingly remark- 

 able as bearing the same relation to the Trinidad B. aureolus, as 

 the Tobagan form of Bulimus ohlongus does to the Trinidad 

 type of that species. There are, therefore, the following forms 

 of Bulimulus aureolus : — 



Var. a typicus, (yellow). 



Var. /9 albescens, (white). 



Var. Y fasciatus, (banded). 



Var. d imperfectus, (small banded). 



Var. £ Baivsoni, (dead white with yellow umbilicus and apex). 



The following are the dimensions of a large example of the 

 typical form : Length, 25 millimetres ; greatest breadth, 10 mill. ; 

 height of aperture, 10 mill. 



I add a figure of var. e. PI. 17, fig. 6. 



A single example of Simpulopsis corrugatus, lately found by 

 me, although not quite adult, has enabled me to ascertain the 

 characters of the dentition of the genus, which resemble those of 

 Succinea more than I had anticipated. The odontophore is 

 moderately large, but the individual teeth are very minute, and 

 resemble those of Succinea, particularly, perhaps, S. ovalis. 



IV. 



A visit recently made by me to the Cerros of Oropuche, in 

 the eastern part of the northern chain of mountains of Trinidad, 

 furnished me with tAvo new forms of Gasteropoda. In the same 

 district, I found specimens of the Diplommatina, previously dis- 

 covered near the Maracas water-fall. Its occurrence in the almost 

 untrodden mountains of Oropuche impressed me strongly in favor 

 of its claims to be considered an indigenous and not an intro- 

 duced species, a question upon which there has been some con- 

 troversy. It seems to me improbable that an introduced species 

 of so delicate a nature as the Diplommatina should be found so 

 far up in these forest-clad hills. 



In the present communication, I include an account of a new 

 Planorhis, a Buliminus, and an Ancylus, lately found by me in 

 Trinidad. 



