TROCHOMORPHA. 129 



convex, sensibly increasing, little shining, sculptured with delicate 

 growth lines ; the last whorl acutely carinated, hardly descending 

 in front, shining beneath. Umbilicus perspective, broad, deep. 

 Aperture diagonal, subrhombic-lunar ; peristome simple, acute, the 

 upper margin obliquely arcuate, lower margin receding. 

 Alt. 7, greater diam. 17, lesser 15 mill. ($w.) 



Rossel Island, Louisiade Archipelago. 



T. nigrans E. A. SMITH, Ann. Mag. N. H. (6) iv, p. 200, t. 13, f 

 9-11, Sept., 1889. 



This species approaches T. papua and T. planorbis and some 

 other species in many respects ; it may be recognized by the dark 

 chestnut color and the white thread-like keel and suture. 



T. RUBENS Hartman. PI. 47, figs. 1, 2, 3. 



Shell umbilicated, the umbilicus deep and tubular, one-seventh 

 the diameter of the shell's base; thin but rather solid, lens-shaped, 

 nearly equally convex above and below the acute, white-edged 

 peripheral carina. Color light horny-buff, more or less tinged and 

 obscurely streaked with tawny-brown, especially below suture and 

 keel, and having a blackish red-brown band just above the white 

 keel (and ascending the spire) and another immediately below the 

 keel. Surface a little shining, lightly marked by growth-strise, but 

 having no spiral striae. Spire convex, slightly conoidal, the apex 

 pale, obtuse. Whorls 5s, a trifle convex, the last not descending, 

 acutely keeled, a little concave just above the keel and more so 

 below it, convex toward the middle of the base. Aperture ax- 

 shaped, purplish-flesh colored inside ; upper lip thin, straight, basal 

 arcuate, becoming thickened at the well arched columella. 



Alt. 6, greater diam. 14J, lesser 13 mill. 



Aura Island, New Hebrides (Layard.) 



Trochomorpha rnbens HARTM., Proc. Acad. N. S. Phila., 1888, p. 

 251, t. 13, f. 5, 5a, 5b. 



The figures and the above description are drawn from the type 

 specimen, which is the individual figured on the plate of the Proc. 

 A. N. S. Phila. cited above. 



T. GODETI Sowerby. PL 30, figs. 26, 27, 28. 



Shell openly umbilicated, the umbilicus one-fifth the diameter of 

 the base; depressed, carinated, the carina acute in front, becoming 



quite obtuse on the latter part of the body whorl. Color tawny or 

 9 



