mazatlan univalves 333 



Family CEEITHIAD^. 



Genus CEEITHIUM, Adam. 



Ceritliium, Adanson, pars.— J£ Sf A. Ad. Gen. vol. i. p. 284.— 

 Shell ^itk short, scarcely recurved canal ; columella not 

 plicated ; paries callous ; operculum Littorinoid, thick. 



381. Cekithium maculosum, Kien. 



Kien. Icon. Conch, p. 36, no. 2-5, pi. 13, f. 3, (non 2.)— Lam. 



An. s. Vert. vol. ix. p. 312, no. Ao.—Mke. in Zeii. f. Mai 



1850, p. 178, no. 39.— (j^on Vertagus Tcaeulosus, Martin.) 

 Cerithium adusturo, (Kien. teste 'fig. non diagn.) C. B. Ad. 



Pan. Shells, p. 1-50, no. 193.— P. P. C. Cat. Prov. 

 Cerithium nebulosum, Sotv. Thes. Conch, sp. 71, pi. 179, f. 60. 

 ? + (var.) Cerithium adustum, Soio. loc. cit. sp. 70, pi. 178, f. 48.— 



(Non Kien. diagu. et f. 2.) 



Kiener accuratelj' described the Mazatlan shell as C. macu- 

 losum, hut unfortimately in his plate named it C. adustum ; his 

 diagnosis of that species (loc. cit. p. 37, no. 26, f. 2 non 3 ;— 

 Lam. An. s. Vert. ix. p. 313, no. 46) being apparently intended 

 for a Eed Sea shell. Sowerby (following Desh. and MJce.) cor- 

 rects the error of the plate, but alters both the species. He 

 changes the name of this to C. nebiilosum, because as he 

 describes the whole family as one genus, he finds this term 

 preoccupied : and he affiliates C. adustum to a Galapagos 

 shell, which is probably only a smooth variety of the present 

 species. The figure is indeed coloured orange brown; but 

 that tint is not mentioned in the description, which accords 

 sufficiently well with the Mazatlan sliell. An analogous species 

 is C. Guinaiciun (Phil.) Soto, from Ld. Hood's Island. 



The Mazatlan species has the first 8 whirls flat, with a 

 divergence of 43", and sculptured with about 15 veiy faint 

 transverse ribs, crossed by about 5 rather strong lirulte. Here 

 and there a varix is formed. Afterwards the costfr change 

 into a row of stout tubercles, rather above the middle of the 

 whirls, sometimes with a few rows of smaller ones on the body 

 and base of the shell. The spiral lirultc become very faint, 

 and are marked by lines of brown broken up into dots. Some- 

 times there are large palches of blackish brown ; sometimes 

 the prevailing hue is light. The shell is generally very broad 

 and gibbous ; but sometimes it is elongated. The dwarf 



