1894. 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



437 



Caeciliaiic.lliiia', witli GeostUhia and Caecilianella, aud Subulmiiue, with 

 Azeca, Ferussacia, Lotveia, Opeafi, Rumina, /^tenor/yra, Pseudohalea^ 

 Melaniella, Spiraxis, Lapthiaria, Suhulina, aud Gleasula as genera. 

 Among tliese Opcas, tliougli represented in the ish^s of the Indian Ocean, 

 the East Indies, and Polynesia, has its greatest devehjjjnient on the 

 American Continent from Mexico to Venezuela, but it also has several 

 species in the (Jreater Antilles; while Spira.ns, another genus of this 

 family, mostly American, is about ecjually represented in tliis archi- 

 pelago and on the continent. The genus Leptinaria, as defined by 

 Fischer and Crosse, is confined to America, and includes all the s])e(;ies 

 of the iintilles hitherto [daced in Toniatrllina, the latter being by 

 them restricted to the Old World. Tlu^ former is about equally repre- 

 sented in middle America and the Greater ^Vntilles. ,Si)npHlopsis is 

 another genus with its metropolis in America, and with a distribution 

 much like Leptinaria. To these may be added the continental Bulim- 

 ulus, with 74 species in Central America and Mexico, which is well 

 rcpresent(Hl in Cuba, Haiti, Puerto liico, and Jamaica, and Polygyra 

 (restricted), with its metropolis in Mexico and the southern United 

 States, but which inhabits Cuba and Jamaica. 



On the other hand, we find that the peculiar terrestrial molluscan 

 fauna of this archipelago has, as Bland has expressed it, "made a 

 strong impression " on the mainland. The following table will show the 

 continental distribution of these Antillean genera: 



JJistribuHon of yencra of Antillean land moUusks. 



Genus or group. 



Tliysanophora.. 



<'epolis 



Hfiiiitroohus . .. 

 Macroceramun . 



Cylindrillii 



Proserpina 



2>.'eocyclotu.s 



Megaloiiia.stoina 



' hoanopoiiia 



'i'lidora 



Chondropoma .. 

 Cololjo.stylus ... 

 fistula .". 



Adaiiisiella 



Kutrochatella* . 



Species 



iu 

 Greater 

 Antilles. 



Species 



of 

 Mexico. 



52 

 5 



12 



54 



168 



6 



34 



17 



58 ! 



29 i 



I 



80 I 



2:t I 



24 



1.3 

 33 



3? 



Species 



of 

 Central 

 America. 



Species found elsewhere. 



2 in Southern States. 



1 in Peru. 



Several in the Bahamas. 



2 or 3 in Lesser Antilles. 



3 in northern S. Am. and Lesser Ant. 



Northern South America. 20 sp. 



1 or 2 in South America; Leeward 



Islands. 

 South America, 4. 

 1 in Trinidad. 

 2iuSoiith America(?) ; afew in Lesser 



Antilles. 

 3 in South Auierica( ?). 



* Several other species of Pneumonopomata are found in Mexico, Central and South America, which 

 liave been referred to Adamsiella, Cistula, Tudora, and Chondro2?oma, which doubtfully belong to 

 these genera. 



Among the fluviatile mollusks there are no genera common to the two 

 regions whose metropolis is in either of them, save Pachycheilus and 

 Heniisinus; but quite a number of species inhabit both the mainland 

 and the archipelago. The same is true of a good many terrestrial forms. 

 The following list gives these species and their distribution: 



