MAZATLAN UNIVALVES 457 



FAMILY FASCIOLAEIAD^E. 



GENUS LATHIEUS, Montf. 



Conch. Syst. vol. ii. p. 531. This genus includes the turrited 

 species, usually ranked with Turbinella, and intermediate 

 between that genus and Fasciolaria. 



Latirus, H. fy A. Ad. Gen. vol. i. p. 152. 



582. LATHIEUS CERATUS, Gray. 



Murex ceratus, Gray, in Wood, Ind. Test. Suppl. pi. 5, f. 15. 

 Turbinella cerata, Gray in Griff. An. King. Moll. pi. 41, 

 f. 5 : Zool. Beech. Voy. p. 114. Ken. Icon. Conch, p. 25, 

 no. 16, pi. 16, f. 1. Eve. Conch. Ic. pi. 7, sp. 37. 

 Latirus ceratus, H. fy A. Ad. Gen. i. 152. 



This shell is rightly described by Kiener as having 3 plaits, 

 but is figured by him with four, and by Reeve (number not 

 stated) with five. The young shell is rather more turrited 

 than L. tuberculatus, Brod. (Proc. Zool. Soc. 1833, p. 7 : Ken. 

 no. 17, pi. 16, f. 2: Bve. pi. 8, sp. 12) also brought from 

 Mazatlan by the same traveler ; and its colour is uniform : 

 else the two species are closely allied, although Messrs. Adams 

 place the latter in another genus, (Peristernia tuberculata, 

 i. 154.) The young shell is more distinctly grooved within 

 than the adult ; with a parietal tooth near the suture, and a 

 labial tooth which may have been mistaken for a plait. The 

 adult measures long. 3*, long. spir. 1'55, lat. 1*53, div. 45. 

 Hal). Mazatlan, Dupetit-Thouars. Galapagos ; under stones 

 at low water ; Cuming. Taboga and Panama ; do. and in 

 crevices of rocks, 12 sp. ; C. It. Adams. Mazatlan : ex- 

 tremely rare ; L'pool Col. 



Tablet 2079 contains the largest specimen. 



GENUS LEUCOZONIA, Gray. 



Proc. Zool. Soc. 1847, p. 136. H. fy A. Ad. Gen. vol. i. p. 164. 

 Turbinella and Monoceros, pars, auct. 



i 583. LEUCOZONIA CINGULATA, Lam. 



Monoceros cingulatum, Lam. An. s. Vert. vol. x. p. 118, no. 1 : 

 Enc. Meth. pi. 396, f. &.Sow. Gen. f. 4: Conch. HI. Cat 

 no. l.Rve. Conch. Syst. pi. 261, f. 4: Conch. Ic. pi. 3, 



Jan. 1857. q q 



