MAZATLAN UNIVALVES 48 
Faminy FASCIOLARIADA:. 
Genus LATHIRUS, Monff. 
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. g A. Ad. Gen. vol. i. p. 152. 
582. LaTHinus cERATUS, Gray. 
Murex ceratus, Gray, in Wood, Ind. Test. Suppl. pl. 5, f. 15. 
Turbinella cerata, Gray in Griff An. King. Moll. pl. 41, 
f.5:—Zool. Beech. Voy. p.114.—Kien. Icon. Conch. p. 25, 
no. 16, pl. 16, f. 1— Rve. Conch. Ic. pl. 7, sp. 37. 
Latirus ceratus, H. & A. Ad. Gen. 1. 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. tubereulatus, Brod. (Proc. Zool. Soc. 1833, p.7: Kien. 
no. 17, pl. 16, f. 2:—Rve. pl. 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, 
. 1.154.) The young shell is more distinetly 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°. 
Hah.—Mazatlan, Dupetit-Thouars,—Galapagos ; under stones 
at low water; Cuming.—Taboga and Panama; do. and in 
erevices of rocks, 12 sp.; C. B. Adams.—Mazatlan: ex: 
tremely rare ; LZ’ pool Col. 
Tablet 2079 contains the largest specimen. 
Genus LEUCOZONIA, Gray. 
Proc. Zool. Soc. 1847, p.136.—H. & A. Ad. Gen. vol. i. p. 154. 
Turbinella and Monoceros, pars, auct. 
583. Levcozonta crneunata, Lam. 
Monoceros cingulatum, Zam. An. s. Vert. vol. x. p. 118, no. 1 :— 
Ene. Méth. pl. 396, f. 4.—Sow. Gen. £. 4:—Conch. Ill. Cat. 
no. 1—Rve. Conch. Syst. pl. 261, £. 4:—Conch. ‘Ee. plies 
J an. 1857. gg 
