MAZATLAN TJNIVALVE9 485 



not easily located elsewhere, it is here used in tlie enlarged 

 sense. The present species approaches very nearly to H. costu- 

 laris, Lam., R. gibbosus, Rve., and R. Califomicus, A. Ad. It 

 is known at once from Cuma costata by the roundness of the 

 ribs, want of keel, and the greater narrowing and recurving of 

 tlie canal. Altliougli apparently of sedentary habits, not 

 eating away obstructions in its shell close to the columella, it is 

 remarkably free from the incrustations which usually cover C. 

 costata. The form of the canal often irregularly approaches 

 Cassis. The operculum closely resembles that of Cuma costata, 

 differing in being somewhat more elongated, the pale margin 

 not so distinctly marked off, and the surface rougher. The 

 largest sp. measures long. 1"12, long. spir. "54, lat. ' 67 div. 55°. 



A broad sp. „ '84, „ '38, „ '65, ,, 65°. 



The most depressed sp. *57, „ '22, „ "56, „ 80°. 



Sab. — Mazatlan ; rare ; L'pool Col. 



Tablet 2278 contains 3 sp. depressed form.— 2279, 3 do. nor- 

 mal shape. — 2280, 3 do. acuminated. In the largest, a portion 

 of the canaliferous rib remains, not eaten away, overhanging 

 the labium. — 2281, 4 sp. shewing the labrum at different stages 

 of the costge. — 2282, 4 sp. with 5, 6, 7 and 8 ribs respectively. — 

 2283, 2 sp. shewing extremes of sculpture. — 2284, 2 sp. with 

 opercula. — 22S5, 2 sp. with adhesions. — 2286, 2 sp. mended 

 after fracture : one has formed a second canal ; the other has 

 twisted it back at an angle of 110°. 



Genus VITHLAEIA, Stvains. 



Treatise, p. 297, 1840. — H. ^ A. Ad. (inter Murices,operc. ign.) 

 Gen. vol. i. p. 74. Shell with very irregidar varices ; oper- 

 culum Purpuroid. 



612. VlTFLABIA SAIEBEOSA, King. 



Murex salebrosus. King, Zool. Jonrn. vol. v. p. 347. — Soik. 



Conch. III. pi. 65, f. 48. — Kien. Icon. Conch, p. 121, pi. 47. 



f. 1. — Lam. An. s. Vert. vol. ix. p. 613, no. 84. — Rve. Conch. 



Ic. pi. 21, f. QS.—Mke. in Zeit.f. Mai. 1850, p. 187. no. 68.— 



C. B. Ad. Pan. ShelU, p. 125, no. 142. 

 Fusus salebrosus, Forbes, Proc. Zool. Soc. 1850, p. 274. 

 Murex vitulinus, G-ra//, Zool. Beech. Vo//. pi. 33, f. 4, 6 ; [non 



Lam. loc. cit. p. 595, no. 53: — = Murex purpura (Chemn.) 



Desh. in nota : = M. miliaris, Gtnel. Dilho. Wood.} 



