98 THE NAUTILUS. 



and Central American species, while the Thysanophora and Opeas 

 are so widely distributed that they have little or no significance. 



I am greatly indebted to Dr. Pilsbry for assistance in determining 

 the specific values and relationships of the different species, and to 

 Mr. George Nelson for the photographs reproduced on the plate. 



The list of species follows : 



Thysanophora selenina (Gld.) CcRcilioides consobrina (d'Orb.) 



Drynuzus insulaz-cygni, sp. nov. Succinea latior C. B. Adams. 



Opeas micra (d'Orb ) Colobostylus nelsoni, sp. nov. 



Brachypodella insultz-cygni, Chondropoma caribbeeum, 



sp. nov. sp. nov. 



Microceramus concisus (Morel). Lucidella pilsbryi, sp. nov. 



DRYMAEUS INSUL^I-CYGNI, sp. nov. PI. VI, fig. 5. 



Shell perforate, oblong conical, thin, straw-colored or white, the 

 last one or two whorls irregularly marked with faint longitudinal 

 streaks of pale brown or pink, generally delicate pink on the reflexed 

 columellar lip. Surface glossy, spirally striated with numerous fine 

 incised lines. Apex with typical Drymaeus sculpture. Whorls 

 6^-7 slightly convex. 



Aperture ovate, oblique to axis of whorls. Peristome simple, 

 slightly expanded below. Columellar surface within the aperture 

 oblique and more or less sinuous. Columellar lip reflexed in a small 

 flat plate above the umbilicus. 



Alt. 30 mm., diam. 13 mm., ap. 1. 14 mm. 



Alt. 28 mm., diam. 12 mm., ap. 1. 13 mm. 



Alt. 24 mm., diam. 11 mm., ap. 1. 11.5 mm. 



Alt. 35 mm., diam. 13 mm., alt. 1. 15 mm. 



Less solid and opaque than D. immaculatus, with sutures more 

 impressed, last whorl shorter. Aperture broader and peristome 

 more convex. The spire resembles in shape that of D. immaculatus 

 from Jamaica. The aperture is like that of D. lilaceus from Porto 

 Rico. The texture resembles that of D. sulphureus from Central 

 America. 



The animal when alive is dark bluish green above, fading to slate 

 gray on the sides. The outer edge of the foot is tinged with green, 

 which changes abruptly to cream color near the central part. 



Types : No. 22877, M. C. Z. 



