BULIMULUS-ANTILLEAN. 39 



thickened within, a common character in Guadelupe shells. B. 

 acutus Leach and simplex Beck were based on shells with a peripheral 

 dark line on a light ground. Gmelin correctly considered these 

 various band forms as specifically identical; and they cannot be 

 said to constitute even varieties in the true sense. Probably all of 

 the color combinations will be found wherever exilis occurs, although 

 one or other usually predominates in each restricted station of the 

 species. Thus out of 44 specimens from Barbados, 36 are yellow or 

 whitish, bandless (mostly dark on the spire), and 8 are 3-banded. Of 

 27 Dominica shells, 10 are light and bandless, 6 are 3-banded; 7 

 are 1-banded ; and the rest are uniform dark shells. In a tray con- 

 taining 79 shells from Guadelupe (Grande Terre), 65 are 1-banded, 

 10 bandless, 4 3-banded. Another tray from Guadelupe contains 7 

 3-banded, 4 1-banded and two dark and bandless examples. Similar 

 variations of the proportions occur in the shells before me from St. 

 Thomas, St. Kitts, Antigua, Tortola, St. Lucia, St. Martins, St. 

 Barts, Vieque, Pto. Rico, Haiti. 



In form, some of the Haitian shells are slenderest, while very 

 stout examples occur (with normal forms) in Dominica, Porto Rico 

 and Barbados. Many Guadelupe specimens are extremely thick, 

 and heavier than those from other localities; but no general rule 

 can be deduced governing the form or solidity, which vary inde- 

 pendent of the color-variation, and largely without regard to geo- 

 graphic position. These variations are doubtless dependent upon 

 the peculiarities of station, individuals inhabiting calcareous districts 

 being heavier than those from volcanic tracts or those poor in lime. 



B. exilis has been reported from Cayenne (Eyries, see Drouet, 

 Moll. Terr. Guyaue Franyaise, p. 62), but no doubt erroneously. It 

 is evident to anyone critically reviewing Drouet's French Guiana 

 list, that lieutenant Eyries mixed shells from the French Antilles 

 with his Guiana material, probably being unaware of the importance 

 of geographic data. The continental localities for species known to 

 be Antillean, incorporated into PfeifFer's works from this source, 

 must all be received with great reserve. 



There is nothing intrinsically improbable in the locality St. Vin- 

 cent, but its confirmation is needed ; on the other hand, the occur- 

 rence of the species on the South American main seems very doubt- 

 ful. 



Var. EYRIESII (Drouet). PI. 12, figs. 52, 53 (type); 54-60. 



Shell perforate, elongate-acuminate, quite thin, somewhat translu- 

 cent, lusterless, of a uniform gray-reddish shade. Smoothish, but 



