MAZATLAN UNIVALVES 525 



Desk, in Lam. An. s. Vert. vol. ix. p. 610, no. 80. C. B. Ad. 

 Pan. Shells, p. 124, no. 141. 



Phyllonotus regius, Stvains. Exot. Conch, pi. 5, f. 15. 

 Murex tricolor, Vol. in Humb. Rec. Obs. vol. ii. p. 300. 



Shell with 6-8 double varices uniting 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 off : the specimens here inserted are from the 

 S. W. Mexican collection. Long. 4*' 6, long. spir. 1', lat. 3*5, 

 div. 100. 



Hah. Acapulco, Humboldt fy Bonpland. Panama ; on mud 

 banks at low water, (teste Eve.) Ouming. 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 fy Havre Coll. 

 Tablet 2504 contains 2 sp. not cleaned. 



671. PHYLLONOTUS PEINCEPS, Brod. 



Murex princeps, Brod. in Proc. Zool. Soc. 1832, p. 175. Sow. 



Conch. III. no. 83, p. 43. Kien. Icon. Conch, p. 56, no. 40, 



pi. 29, f. 1. Desk, in Lam. An. s. Vert. vol. ix. p. 609, 



no. 79. Eve. Conch. Ic. pi. 6, f. 23, pi. 36, f. 24. 



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



smaller palmulse, 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. The Mazatlan specimens are 



much more elevated than those 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 iiicrusted with coralline, coral, Yermetidse, &c. Oper- 



