MAZATLAK UNIVALVES 525 



Besh. in Lam. An. s. Vert. vol. vs.. p. 610, no. 80.— C. B. Ad. 



Fan. Shells, p. 124. no. 141. 

 Phyllouotus regius, Sioains. JExot. Conch, pi. 5, f. 15. 

 Murex tricolor, Val. in Humh. Rec. Ohs. vol. ii. p. 300. 



Shell with 6-8 double varices iiniting near the suture, where 

 the posterior canal and two spines are open ; about 10 others 

 lie behind the labrum, still open, the upper one on the siphonal 

 canal crossing the others. These are longer and narrower 

 than in M. bicolor. Labrum deeply channeled to correspond. 

 No false varix between the others. Labium expanded, not 

 much raised. Siphonal canal scarcely bent, almost covered, 

 leaving a small umbilicus. Mouth pinkish red, spotted with 

 black on the edges. Surface covered with subgranular spiral 

 lines. About 300 specimens sent in the L'pool Col. were acidu- 

 lated and sold oflP : the specimens here inserted are from the 

 S. W. Mexican coUection. Long. 4 '6, long. spir. 1', lat. 8 '5, 

 div. 100". 



Hah. — Acapulco, Humholdt 8f Bo7ipland. — Panama ; on mud 

 banks at low water, (teste Kve.) Cuming. — Panama ; in 

 crevices of rocks between low water marks of spring and 

 neap tides, common'.and fine, (5 "3 by 4" 2 in.) ; C. B. Adams. — 

 S. W. Mexico, P. P. C. — Mazatlan ; not uncommon; 

 L'pool Sf Havre Coll. 



Tablet 2504 contains 2 sp. not cleaned. 



671. Phyllonotus peinceps, Brod. 



Murex princeps, Brod. in Proc. Zool. Sac. 1832, p. 175. — Soto. 

 Conch. III. no. 83, p. 43. — £:ien. Ico7i. Conch, p. 56, no. 40, 

 pi. 29, f. 1. — Desh. in La}7i. An. s. Vert. vol. ix. p. 609, 

 no. Td.—Rve. Conch. Ic. pi. 6, f. 23, pi. 36, f. 24. 



Shell with about 7 varices, each with 3 pinnate fronds, and 

 smaller palmuliE, open from the labrum, which is channeled 

 and armed with white teeth within. On the siphonal canal 

 (which is broad, scarcely bent, and almost closed) are two 

 fronds, of which one crosses the lower labial frond. Labium 

 short, and, with the mouth, white with a narrow brown rim. 

 Columella scarcely bent. Posterior canal short, not foliated, 

 marked off by a parietal tooth. Tlie Mazatlan specimens are 

 much more elevated than tliose figured by Sow. Kien. and Rve. 

 It is presumed that this creature is very sluggish in its habits, 

 as the whole shell, as far as the penultimate varix, is usually 

 thickly iucrusted with coralline, coral, Vcrmetidee, &c. Oper- 



