HELIX-STEGODERA. 11 



H. TRISINUATA Martens. PL 1, figs. 12, 13, 14. 



Shell umbilicate, depressed, the spire low ; color dark brown, 

 opaque ; aperture very oblique, obstructed by four teeth, the per- 

 istome white, continuous, expanded and reflected. 



The form is depressed convex above and below, obtusely carinated 

 above the middle of the body whorl. It is solid, opaque, dark 

 brown or sometimes yellowish-brown, darker on the latter third of 

 the body-whorl. Surface lusterless, covered all over with a micro- 

 scopic granulation, and with a rather coarse pattern of tubercles ar- 

 ranged in very oblique rows, often forming short folds at the periph- 

 ery, and disappearing in the vicinity of the umbilicus. Spire low, 

 rounded, flattened at apex ; apical whorl large (commencing with a 

 width of f mill.), microscopically granulated. Suture slightly im- 

 pressed, from apex to termination. Whorls 4J, the inner slightly 

 convex, the outer two flatter ; they increase slowly in width, the last 

 narrowing toward the aperture ; last whorl obtusely carinated above 

 its middle, descending anteriorly, becoming free from the preceding 

 at the aperture, and deeply grooved or scrobiculate behind the outer 

 lip by an oblique pit within the umbilicus, a deep narrow curved one 

 below the periphery, and a small one just above it. Aperture sub- 

 horizontal, triangular, dark purplish-brown inside, the peristome 

 pure white, broadly expanded all around, the basal margin bearing 

 a square tooth, the outer margin a strong entering fold, with a 

 smaller one above it, the parietal wall elevated, emarginate, with an 

 inward-projecting tubercle or angle. Umbilicus deep, as wide within 

 as at its opening. 



Alt. 11, diam. maj. 19, min. 17 mill. 



Alt. 9, diam. maj. 16 mill. 



Island of Hong-Kong ; Ma-aa-shan Mts., Province of Kwang-tung > 

 China. 



H. trisinuata MARTENS, Die Preuss. Exped. nach Ost-Asien, 

 Landschn., p. 50 (1867). PFEIFFER in Novit. Conch, iii, p. 352, t. 

 82, f. 16-18 ; Monographia v, p. 412 ; vii, p. 465. MOLLEN.DORFF, 

 in Jahrb. d. Mai. Gesell. viii, p. 302, 303 ; and 1. c. xi, p. 309, 1884. 

 Polygyra trisinuata Mart., GREDLER, Mai. Blatt. 1887, p. 129. 

 H. trisinuata var. sculptilis MOLLENDORFF, Jabrbucher, 1884, p. 

 310, t. 4, f. 7. 



Mollendorff says (Jahrb. d. D. Mai. Gesell. 1884, p. 310) that H. 

 trisinuata is found only near Cape d'Aguilar near the village of Shek- 

 ko, on the Island of Hong-Kong. It-lives deep in rocky debris, and 



