the Caribcean Islands. 531 



Testa adiaphana, ovato-conica, spira elevata. Apertura sub- 

 ovalis. Columella simplex, ad basin truncata.* Columellarium 

 amplum. Peritrema saepissime simplex, rarissime submargina- 

 tum ?+ Umbilicus evanidus. 



Achafina undulata. 



Ach. flavido-fuscescens ; cervice supra pallidiori, basi coeru- 

 lescente; tentaculis cceralescentibus, apice flavescentibus, ad 

 radices verrucosis ; solea pallida, margine fuscescente ; pallio 

 margine superno ferrugineo ; coUari albo obscure irrorato. 



Testa ovato-oblonga, cinereo-flavescens, striis undulatis ferru- 

 gineo-nigris : spira obtusa, 7-voluta; columella nivea, columel- 

 lario et peritremate saturate castaneis." 



Pullus pallidior. Testa flavo-fuscescens, diaphana, inferne 

 trifasciata, fasciis mox (anfractu altero adjuncto) obtectis, 

 evanidis. 



Species affinis. A. melastoma. Swains. 

 Long, testae. 2 uiic. \\ lin. 



Habitat in insula nostra parva cui noraen " Union," arbori- 

 bus serpens. Species formosa. 



* Mr. Swainson, in liis description of Jch. fasciata, has made a remark 

 which it is necessary to keep in mind while examining the young of the 

 jichatineB. In the young shells of Ach. fasciata, the base of the columella 

 unites with the termination of the outer lip, making the aperture entire, simi- 

 lar to the lengthened Helices, but as the shell advances in growth the base of 

 the Columella becomes thick, and detached as it were from the marginal line, so 

 as to produce an intervening notch, and thus gives the old and the young shell 

 not only an appearance of being distinct species, but of belonging to separate 

 genera. The same law probably takes place through the whole genus. It 

 certainly is observed in the species before us, the young of which might easily 

 be referred to the Bulimuli, Leach. 



+ Mr. Donovan, at plate 149 of his Naturalist's Repository, has figured a 

 species which recedes from the characters usually laid down for this genus, in 

 having the Peritrema incrassate, aud somewhat margined. The figure exhibits 

 no sign that the shell has suffered injury, or I should have supposed it to be a 

 Bulimus, neaily arrived at maturity; and on further inspection this may 

 prove to be the case, as the larger Bulimi are subject to distortions at the bae 

 of the columella. 



2l 2 



