202 HELIX-CAM^ENA. 



forming the nucleus, the junction of which with the after-growth is 

 distinctly marked by a line ; the next whorl is nearly flat ; the last 

 Avhorl is convex above, bluntly carinated at the periphery, convex 

 below, and generally descends a trifle (1 to 2 mill.) in front. Aper- 

 ture oblique, lunate, livid-bluish inside ; entire peristome expanded, 

 reflexed, the basal margin straightened, (appearing curved forward 

 in the middle, seen from beneath), the columellar margin a very 

 short curve at right angles to the basal lip, very broadly expanded 

 over the narrowly perforated axis, entirely or nearly closing the um- 

 bilicus. 



Alt. 36, greater diam. 56, lesser 46 mill. 



Cambodia- 



H. illustris PFR. P. Z. S. 1862, p. 269, t. 36, f. 8 ; Monogr. Hel. 

 Viv. v, p. 275 ; Novit. Conch, ii, p. 208, t. 55, f. 1-3. MARTENS 

 Ostas. Landschn. p. 328. DOHRN Krister's Conchyl. Cab. p. 581, t. 

 171, f. 4, 5. 



A large, solid species, either reddish-brown or yellow in color and 

 often encircled at the periphery by a brown zone. On one speci- 

 men before me this is replaced by a cream-colored line. The spe- 

 cies is about mid-way between H. cicatricosa and H. ochthoplax in 

 character of contour and sculpture, and is about equally allied to 

 each of them. Dohrn is undoubtedly right in referring it to Cam- 

 cena instead of Pliania. I had arrived at the same conclusion be- 

 fore seeing his note in the Conchylien Cabinet. 



H. OCHTHOPLAX Benson. PI. 61, figs. 23, 24. 



Shell deeply, half-covered umbilicate, depressed, convex above, 

 more convex beneath, thick lens-shaped, rather obtusely carinated 

 at the periphery, rather thin, opaque, with a thin yellow epidermis. 

 Surface obscurely malleated all over, the sculpture consisting of 

 low, rather indistinct and irregular revolving wrinkles. Spire IOAV, 

 convex, apex plane, suture superficial. Whorls barely 5, nearly 

 flat, regularly increasing, the earlier 2J forming the nucleus, which 

 is rather large, (about 12 mill, diam.) and which is separated 

 from the after-growth by a distinct arcuate line. The last whorl is 

 depressed, carinated at the circumference, and does not descend in 

 front. The aperture is oblique, lunate, livid flesh-color inside ; 

 peristome thin, expanded, the basal margin seen to be arched a 

 little forward when viewed from beneath ; columellar margin short, 



