140 GASTROPODA. [Aspidobranchia. 



Genus 3. MONILEA, Swainson, 1840. 



Monilea, Swainson, " Shells and Shell-fish," 1840, 352. Type : Trochus 

 calliferus, Lam. Monilea, Swainson, Man. Conch. (1), xi, 12, 246. Talo- 

 pia, Gray, 1842. 



Shell solid or thin, depressed conical, sharply striate and spirally 

 lirate, umbilicated, having a more or less developed callous ridge 

 or funicle revolving on the inner side of the whorl within the um- 

 bilicus, and terminating at the columella, the edge of which is reflexed 

 over it. Outer lip sharp, lirate within. Columella sinuous, more or 

 less crenulate on its edge, terminating in a point or denticle at the 

 base. 



The Indian Ocean is the habitat of most of the forms, but some 

 are found in the Pacific. 



KEY TO SPECIES. 



A. Spiral lirse numerous, fine ; margin of umbilicus not crenulate : 



colour crimson . . . . - - . - . . carmesina. 



B. Spiral lirse few, sharply elevated ; margin of umbilicus cremilate ; 



colour whitish, with brown streaks . . . . . . egena. 



1. Monilea carmesina, Webster, 1908. Plate 38, fig. 24. 



Trochus carmesinus, Webster, T.N.Z.T., xl, 1907 (1908). 256, pi. 20, f. 16-18. 



Shell small, depressed trochiform, umbilicated, crimson, spirally 

 striated, shining, rather solid. Sculpture of the post -embryonic whorls 

 consisting of fine somewhat unequal spiral striae, with linear inter- 

 spaces, about 20 on the upper surface of the body-whorl, and a similar 

 number on the base ; a narrow smooth band round the peripheral 

 angle ; umbilicus margined by a broadly rounded funicle. Colour 

 pale pink, with radiate crimson streaks on the second and third whorls, 

 the succeeding whorls are crimson with occasional lighter streaks, 

 periphery of body-whorl with semicircular small white spots, usually 

 2 together, and at subequal distances ; aperture, iridescent within ; 

 umbilicus and columella white. Spire broadly conical, about H times 

 the height of the aperture ; outlines lightly convex. Protoconch of 

 1| smooth whorls, small and flattish. Whorls 5. first slowly, then 

 more rapidly increasing, the upper half convex, the lower slightly 

 concave ; periphery of body-whorl roundly angled ; base almost flat. 

 Suture superficial. Aperture oblique, subrhomboidal. Outer lip de- 

 scending, very lightly convex, and forming an acute angle with the 

 faintly arched basal lip ; both strengthened inside by a thin callus. 

 Columella oblique, straight, with a distinct tubercle above, and a 

 small denticle at the base. Umbilicus moderate, deep, extending to 

 the initial whorl, about one-sixth of the greatest diameter, the descend- 

 ing cord distinctly visible. Opcrculum unknown. 



Diameter Maj., 8 mm. ; min., 6-25 mm. : height, 5 mm. 



Animal unknown. 



Type in Mr. Webster's collection. 



Hob. Russell ; Cape Palliser, found in shell-sand. 



