392 MAZATIAN TTNIVALTE8 



JETab.—W. Columbia ; in sandy mud, 16 fin. : Cuming. — Maz- 

 atlan ; not uncommon ; L'pool Col. 



Tablet 1882 contains 8 sp. different ages and markings. — 

 1883, 3 do. colour scarcely developed. — 1884, 4 sp. rather more 

 slender.— 1885, 4 sp. mended after fracture, (one with, a fresh, 

 separate canal.) — 1836, 3 do. spire bent. — 1887, 1 sp. pierced by 

 a Proboscidifer. — Six of the above sp. have the normal opercula 

 in situ ; tablet 1888 contains 2 sp. with abnormal opercula in 

 situ, and one normal operculum separate. 



Genus DEILLIA, Ghay. 



Fig. Moll. An. p. 73, no. 3.— fl". Sf A. Ad. Gen. vol. i. p. 89. 



Clavatula, pars, Lam. The operculum is Purpuroid in Clava- 

 tula, Pleurotomoid in Drillia. Canal very short. The group 

 is remarkable, among marine shells, for the number of black 

 species. 



459. DfilLtlA INCEASSATA, SoV3. 



Pleurotoma incrassata, Soio. Proc. Zool. Soc. 1833, p. 138. — 

 Miill. Syn. Nov. Test. Viv. p. 115. — Sve. Conch. Ic. pi. 9, 

 f. 76.— ih-e. in Zeit.f. Mai. 1851, p. 19, no. 90.— C. B. Ad. 

 Pan. Shells, p. 144, no. 175. 



Crassispira (Drillia) incrassata, H. Sf' A. Ad. Gen. i. 91. 



Pleurotoma Bottae, Kien. Icon. Conch, p. 33, no. 26, pi. 15, f. 2. 



The solitary Mazatlan specimen differs from Kiener's figure 

 of M. Botta's supposed unique shell, in being quite black, with 

 the labrimi serrated, sharp, and incurved at the edge, then 

 very much thickened ('18 in.) ; behind very thin, nearly tran- 

 sparent. Posterior callosity distinct. The aspect of the sheU 

 is like a very large D. luctuosa, with very fine granulose radia- 

 ting lines, about 18 in a whirl. A closely analogous form 

 from the ^Y. Indies, is probably the D. gibbosa, Chem. ele- 

 gantly figured by Kien. Icon. Conch, pi. 16, f. 2. as his own 

 species ; the error being corrected by Rve. sp. 30. Long. 1'64, 

 long. spir. "83, lat. '68, div. 30". 

 Sab. — Panama and Monte Christi ; in sandy mud 6 — 10 fin. ; 



Cuming. — Panama, 1 sp. C. B. Adams, — Mazatlan, Botta : — 



do. ; 1 fresh sp. ; L'pool Col. 



Tablet 1889 contains the specimen. 



