HELIXr-CHLORITIS. 257 



The shallower sutures and narrower umbilicus separate this spe- 

 cies from H. majuscula. 



Group of H. quercina. 



Depressed-globose with conoidal spire and narrow umbilicus ; the 

 apex prominently exserted. Surface covered with short rigid hairs ; 

 unicolored brown. 



The Exserted apex of this species is unique in Chloritis, where as 

 a rule the apex is planorboid or sunken. The earlier whorls seem 

 to be smooth, as in Planispira. Compare also H. majuscula and isis. 



H. QUERCINA Pfeiffer. PL 37, figs. 48, 49. 



Shell narrowly, half-covered umbilicate, depressed-globose with 

 conical, acute spire; chestnut-brown, unicolored; surface covered 

 with short, stiff hairs, about i millim. apart. 



Opaque, strong but rather thin, the surface in fresh specimens 

 nearly lusterless and covered with stiff wirey hairs about a half 

 millimeter in length, worn off on the spire and around the umbili- 

 cus. In rubbed shells the hair-scars may still be seen on the surface. 

 Spire elevated, acute, its sides slightly concave ; apex pointed, pro- 

 jecting; suture impressed, whorls 5? to 6, convex, the last sub- 

 globose, but often very obtusely angled at the periphery. In front 

 it descends a trifle. Aperture somewhat oblique, the peristome 

 seen in profile to be arched backward in the middle. The aperture 

 is flesh-colored inside, of a rounded-lunar form ; peristome white, 

 narrowly reflexed all around, dilated triangularly at the columellar 

 insertion, half covering the narrow umbilicus. 



Alt. 23, greater diam. 29, lesser 26 mill. 

 Shortland, Faro and Ysabel Islands, Solomon Is.', (Admiralty Is. /) 



H. quercina PFR. Proc. Zool. Soc. Lond. 1856, p. 382 ; Novit. 

 Conch, i, p. 108, t. 31, f. 1, 2; Monog. Hel. Viv. iv, p. 247. IT. 

 Hombroni PFR. P. Z. S. 1856, p. 382; Novit. Conch, i, p. Ill; 

 t. 31, f. 9-11 ; Monog. Hel. Viv. iv, p. 262. DOHRN in Conchyl. 

 Cab. p, 583, t. 172, f. l-l.H. janellii HOMBR. & JACQ. Voy. Pole 

 Sud, Zool. v. p. 8, t. 4, f. 15-18, (not H. JaneUii Le Guillou, a 

 species of Xanthomelon). H. ( Camcena} hombroni Pfr. E. A. SMITH 

 P. Z. S. 1885, p. 594. 



The typical quercina is rather globose, the aperture of a rounded- 

 lunar shape. The form called H. Hombroniby Pfeiffer is connected 

 by insensible gradations with it, and must be considered as at most 

 a mere variety. 

 17 



