196 DRILLIA. 



D. NIGERRIMA, Sowb. PI. 14, figs. 91, 89, 88, 94, 



Shell very dark chocolate; whorls longitudinally ribbed, the 

 ribs terminating on a nodulous periphery, above which the sur- 

 face is smooth and slightly concave, lower portion of body-whorl 

 with revolving striae. Length, 22 mill. 



Panama to Mazatlan. 



D. cornuta, Sowb., is founded upon a specimen in which the 

 callous deposit at the top of the aperture is very thick. D. uni~ 

 color, Sowb. (fig. 89), D. rustica, Sowb. (fig. 88 \ D. tiarella, 

 Kiener (PL 32, fig. 19), D. rugifera, Sowb. (PL 12, fig. 22), and 

 probably D. Hanleyi, Carpenter (described from a single im- 

 mature specimen), are identical. 



Var. HARFORDIANA, Reeve. PL 14, fig. 94. 



Whorls with a narrow yellowish band on the periphery. D. 

 obvellata, Carpenter, described from a single young shell, is 

 probably equivalent to this variety. 



D. BICOLOR, Sowerby. PL 14, fig. 100. 



Shell chocolate-brown, with a yellowish band just below the 

 periphery; sculpture as in other species of this group. 



Length, 20 mill. Panama; Galapagos Islands. 



D. GRANULOSA, Sowerby. PL 14, fig. 1. 



Whorls concave and smooth above the periphery, ribbed 

 below it, ribs crossed by fine granulated revolving lines ; light 

 yellowish or pinkish brown. Length, '75 inch. 



Panama, Bay of Monti j a. 

 D. PALLTDA, Sowerby. PL 14, fig. 8. 



Ribs deflected at the periphery but continuous to the suture, 

 sharp and rather close, interstices with fine revolving striae ; 

 sinus broad and deep ; canal very short, a little recurved ; white. 



Length, 20-30 mill. Panama. 



D. ZEBRA, Lamarck. PL 14, figs. 2, 6, 5, 11, 12, 7, 10 ; PL 15, 

 figs. 15, 18. 



Shell orange-, chestnut- or chocolate-color, the duplicate rows 

 of tubercles on the periphery white, with frequently one or two 

 inferior white bands on the tubercles of the lower part of the 

 body-whorl. Length, 20 mill. West Indies. 



A very common species, referred by Kiener to Mauritius, and 



