84 HELIX-ACAVUS. 



istome, the entire columella and a broad band across the parietal 

 wall are blackish-brown. Alt. 33, greater diani. 52, lesser 37 mill. 



Ceylon. 



H. waltoni REEVE, Proc. Zool. Soc. Loud. 1842, p. 49 ; Conch. 

 Syst, ii, t. 166, f. 23 ; Conch. Icon., f. 372. PFR. Monographia i, p. 

 19 ; Kiister's Conchyl. Cab., p. 267, 1. 121 , f. 1-3. P. & F. SARASIN, 

 Ergebnisse naturwissensch. Forschungen auf Ceylon i, 2tes Heft, 

 1888. (Embryology.) 



A lovely shell, of peculiarly beautiful and effective coloration. 

 The angular patches of hydrophanous epidermis are characteristic, 

 but unfortunately my artist did not reproduce this feature in the 

 figures. 



o 



H. SKINNERI Reeve. PI. 18, figs. 17, 18, 19. 



Shell depressed-globose, the spire very low, small, obtuse ; peris- 

 tome very greatly thickened, violet or lilac in color. 



The shell is much smaller than that of H. waltoni, of an inflated- 

 depressed form, the spire flat and obtuse, projecting but slightly 

 above the body-whorl. Whorls 83, the earlier 2 forming the nu- 

 cleus or embryonic shell, the post-embryonic growth consisting of a 

 little less than one volution. This body-whorl is globose-depressed, 

 descending in front, inflated beneath. The color is dull chestnut- 

 brown, the thin epidermis worn off on the base, showing the pink- 

 ish-gray substance of the shell. The epidermis, where not Avorn, is 

 seen to be closely flecked with golden specks. The surface is luster- 

 less ; there are numerous little-raised encircling ridges or cords on 

 the body-whorl, and under a strong lens the surface is minutely 

 granulate ; the whorls of the spire are decussated by subobsolete 

 spiral lines crossing growth-stride. The aperture is very oblique, the 

 interior, the parietal wall, the columella and lip of a violet or lilac 

 color. The outer lip is slightly expanded, its face thickened by 

 a callous growth extending 5 millimeters or more in front of the 

 expansion. Alt. 21 greater diam. 36, lesser 26 mill. 



Ceylon. 



H. skinneri REEVE, Conch. Icon., f. 1387. PFR. Monographia 

 iv, p. 219. HANLEY & THEOBALD, Conch. Ind., t. Ill, f. 1.- 

 Acavus skinneri FFLD. in Zool-bot. Ges. AVien 1869, p. 876. 

 SEMPER, Reisen in Archip. Philippine!!, Land Moll, ii, p. 100, t. 

 12, f. 7 ; t. 16, f. 5. (Anatomy.) 



