DRYM^EUS, MEXICO AND CENTRAL AMERICA. 29 



The shells from Curayao often lack the subsutural and umbilical 

 markings, and show traces of a peripheral band (fig. 32), but occa- 

 sionally lack all spiral bands ; the apex generally white. They are 

 readily distinguishable from D. elongaim Bolt., which occurs on the 

 same island, the only locality to my knowledge where the two are 

 associated. 



Form parvus Lea. (PI. 25, figs. 37, 38 ; vol. XI, pi. 25, f. 58.) 

 In Colombia, at Carthagena and Barranquilla, a very pale form 

 occurs, the purple on spire either faint or of typical intensity 

 oblique streaks varying from numerous to very few, of paler tint 

 than typical ; spiral bands faint, subobsolete in the adult, subsutural 

 and umbilical bands wanting ; outer lip with an ochraceous border 

 inside. 



Lea's type specimen of B. parvus (see vol. XI, pi. 25, fig. 58), is 

 a half-grown shell, dead and lusterless, with purple tip, radially 

 striped base and with a single narrow, occasionally interrupted tawny 

 band on the upper whorls, with some spots indicating the presence of 

 the other band mentioned in the description ; the periphery is ab- 

 ruptly angular; whorls 5 J ; alt. 13, diam. 7 mill. It corresponds 

 exactly with young of the form figured on pi. 25, figs 37, 38. The 

 type of parvus is no. 105077 U. S. National Museum. The shell has 

 been broken and repairt, 1. 



I have not seen specimens from Yucatan, but there is no doubt of 

 their essential identity with multilineatus, as they have the same form, 

 size and coloration, "apex violet-bluish." 



III. SPECIES OF MEXICO AND CENTRAL AMERICA. 



Of the 50 or more species of the genus known from this area, all 

 of which the apices have been examined show the grated sculpture 

 typical of Drymceus. The species have been distributed among var- 

 ious subgenera by authors ; thus Dr. von Martens, in his excellent 

 account in the Biologia Centrali Americana, recognizes the subgenera 

 DrymczuS) Mesembrinus, Mormus and Scutalus, though he evidently 

 lays no great stress upon them ; and previous authors accept even 

 more groups. Of these subgenera, Scutalus is a subordinate group 

 of Btdimuhtt) and is here misapplied ; the type of Mormus probably 

 has no close genetic relation to Mexican species ; and between Dry- 

 mceus and Mesembrinus there is a complete chain of intermediate 

 forms. Under these circumstances, subgeneric divisions having any 



