FAMILY CRYPTOSTOMID^ SIGARETUS. 153 



FAMILY CRYPTOSTOMID^. 



Animal with the eyes at the external base of the tentacles. Marine. Shell either external 

 or internal, ear-shaped, much depressed, with a very large aperture ; in some genera, 

 the shell entirely tuanting. No opercle. 



GENUS SIGARETUS. Lamarck. 



Animal oblong, convex above, plane beneath ; mantle very large, emarginate in front ; head 

 wide, with two conic tentacles. Gills composed of two pectens. Vent and generative 

 organ on the anterior right side, that of the male being very voluminous. Shell internal, 

 much depressed: aperture large; spire small, flattened, lateral; lip thin and trenchant ; 

 pillar short and spiral. Two lateral muscular impressions. 



SiGARETUS PERSPECTIVUS. 



PLATE VIL FIG. J5C. A. B. 



(STATE COLLECTION.J 

 Sigaretus pefspecUvits. Say, American Conchology, pi. 25. Subsequently Calt/ptostorrvi. 



Description. Shell moderately large, ovate-elongate, depressed. Surface with numerous 

 impressed transverse slightly undulated lines, which are crossed by revolving stris which be- 

 com.e obsolete beneath. Aperture more than three-fourths of the entire area of the shell. 

 Whorls three : spire depressed, smooth, exhibiting the whorls almost to the summit ; suture 

 distinct, but not deeply impressed. 



Color. Most usually milk-white, sometimes tinged with brown ; within smooth and polished, 

 and faintly iridescent. 



Length, 0-9- 1-5; of aperture, 0-7 -0-9. 



This is a southern species, as far as I can learn ; not having been as yet found to the north 

 of the coast of this State. It is not unfrequent on the seacoast of Long island, near Rock- 

 away. 



{EXTRA-LIMITAL. ) 



S. haliotoideus. (Gould, lavert. Mass. p. 244, fig. 158. S. oxlnoc, Coutuouy.) Shell small, ob- 

 liquely ovate, pellucid, while, compressed, smooth: aperture very large; whorls two. Length, 

 0*5: width, 0'4. Stomachs of fishes. Coast of Massachusetts a7id Europe. 



S. maculatus. (Say, Am. Conch, pi. 25.) Shell with numerous transverse hardly undulated im- 

 pressed lines and longitudinal wrinkles: spire hardly proimnent, slightly convex; whorls about 

 three; suture a simple impressed line. Color, whitish, with two bands of pale rufous spots, and a 

 rufous band near the suture : smaller than the preceding. Southern Coast. 

 Fauna — Part 6. 20 



