518 MAZATLAN UNIVALVES 
663. PISANIA RINGENS, /ve. 
Buccinum ringens, Rve. Conch. Ic. pl. 7, sp. 45.—C. B. Ad. 
Pan. Shells, p. 71, no. 63.—(Non PaAil. in Zeit. f. Mal. 1851, 
p. 59.) 
(Cantharus) Tritonidea ringens, H. & A. Ad. Gen. i. 85. 
This species (if it prove such) differs from P. sanguinolenta 
in the inconstancy of its characters. Of the three Mazatlan 
specimens, one would pass for a dead P. sanguinolenta, the 
second is intermediate, the third nearly as ringent as Reeve’s 
figure. They have 9, 10 and 11 tubercular ridges respectively. 
Spire rather more depressed : infrasutural tubercles stronger, 
with the depression narrower: labral serrations not projecting : 
canal more twisted: mouth white: warts fewer, in two irregu- 
lar rows, of which the inner are elongated. The more typical 
sp. Measures long. ‘84, long. spir.°19, lat. °64, div. 70°. 
Theaberrantsp.,, 1°12, i uy Pic Loree a Ee 
Hab.— Panama; on rocks at low water ; Cuming.—Do.; 
under stones near low water of neap tides, common; 
C. B. Adams.—Mazatlan ; 3 dead sp.; L’pool Col. 
Tablet 2465 contains the two specimens above measured. 
Genus MUREX, Linn. 
664. MurEex PLICATUS, Sow. 
Proe. Zool. Soc. 1840, p. 139:—Conch. Ill. p. 2, sp. 15, f. 6.— 
Rve. Conch. Ic. sp. 87, pl. 21, f. 87: (non pl. 22, f. 87, sp. 97 
pro 87 bis; non sp. 97 pl. 24.) 
?=Murex unidentatus, Whe.* in Zeit. f. Mal. 1850, p. 186, 
no. 66; (non Sow. Conch. Til. f. 52.) 
Comp. M. ternispina, Mke.* loc. cit. no. 67; (Pnon Lam.) 
Only one dead specimen of this shell was found. It is 
remarkable for the long spines on the base and canal, while 
those on the spire are very short. Long. 2°3, long. spir. *€5, 
lat.1°3, div. 80°. ; 
Hab.—Gulf Nicoya; in coarse sand, 12 fm. Cuming.—Mazat- 
lan; one dead sp.; L’pool Col. 
Tablet 2466 contains the specimen. 
* Menke says of his M. unidentatus, that it is the shell quoted by him in 
his Moll, Nov. Holl. no. 109, as M. crassispina. This and his M. ternispina are 
probably either varieties of M. plicatus, or imported from his purchased box, as 
both the original species are E, Indian, 
