232 MAZATLAN UNIVALVES 



Comp. Trochus eximius, Hve. Proc. Zool. Soc. 1842, p. 185. 



(Payana, sandy mud, 10 fm. Mns. Cuming.) 



This beautiful species is characterized in sculpture by a more 

 or less sharp angular keel, at about 3-5ths of the breadth of 

 the penultimate whirl, the whole surface being covered with 

 very fine subgranular spiral striae ; basal periphery at a rounded 

 angle ; base with about 9 distant, nearly smooth and scarcely 

 raised striae. Colouring variegated with ashy and light orange 

 brown, very rarely wholly of a rufous tinge, stained about the 

 granules and on the basal lines with lustrous purplish red, also 

 with rich orange. The first whirl is depressed, smooth, round- 

 ed; gradually passing into very coarse decussation, leaving 

 deep pits between ; these pass into three strongly nodulous 

 ribs, the lower gradually changing into a keel, small ones 

 developing between the others, and both nodules and ribs 

 gradually subsiding into the typical state. The young shell is 

 of a uniform orange brown or reddish tinge. Whirls 10. Very 

 few specimens possessed the operculum, which is extremely 

 thin, of many whirls (15 in a shell of 9 whirls,) with very 

 delicate radiating striae, somewhat curved, and most developed 

 near the margin of each whirl. Long. 1', lot. "92, div. 65. 

 Hab. Mazatlan ; common ; L'pool fy Havre Coll. 



Tablet 1118 contains 4 sp. various ages. 1119, 2 sp. extreme 

 forms, div. 60-80. 1120, 5 sp. shewing base and variations 

 of sculpture. 1121, 2 sp. with hermit crabs. 1122, 1 sp. with 

 operculum. 



Specimens skewing colour. 1123, 4 sp. dark, variegation in 

 large pattern. 1124, 3 do. with narrow streaks of light. 1125, 

 3 do. nearly uniform, dark. 1126, 3 do. light and dark equal. 

 1127, 3 do. light predominating. 1128, 3 do. nearly uniform, 

 light. 



290. TEOCHUS MAC-ANDEE^E, n. s. 



T. t. subelevatd, conicd, anfractibus convexiusculis, sutwrd dis- 

 tinctd ; rubrd, maculis pallidioribus : liris spiralibus nodosis 

 cinctd, in anfr. penult, vi. quarum inferiores du&paullum majores 

 sunt ; inter 'stitiis impressis, lirulis interdum intercalantibus, ; 

 tuberculis confertis, rotundatis, extantibus ; peripkerid mx an- 

 gulatd ; basi lirulis vix granulosis, circiter xi. ornatd, inter- 

 stitiis latis ; columelld hand insculptd, parum contortd t regione 

 umbilicali impressd. 

 VAE. t. rufo-fuscd, undatim pallidiore ; basi rubro. 



