GASTROPODA 



559 



N. decemcostata (Say). Shell with 6 whoils, with 10 rounded re- 

 volving ridges on the lower whorl and 2 on the upper; color white; 

 ridges horn-colored ; length 75 mm. ; width ^45 mm. : Cape Cod and 

 northwards, in rather deep water, often thrown up on the beach. 



Family 5. TUEBINELLIDAE. 



Shell fusiform or pear-shaped; aperture elongate, with a long 

 siphonal canal; central tooth of radula with 3, laterals with 2 cusps: 

 about 8 species on the Atlantic coast. 



1. BuSYCON Bolton {Fulgur Montfort). Conchs. Shell large, with 

 a short spire and a very large lower whorl, which tapers below into a 

 lang twisted canal; 



aperture large; outer ^msssm/ ////>>. A\X\\lilil~fWJ~]V^^>^G[^^AiD\^) 

 lip thin and smooth; 

 whorls 6: 5 species on 



the eastern coast of ^^S. 879 — Egg capsules of Busycon canaliculatum 



(Rogers). 



the United States; egg 



capsules lens-shaped, about 25 mm. wide, attached in a row to a common 



chord (Fig. 879). 



Key to the species of Busycon here described: 



Gi No sutural canal. 



h. Shell dextral B. carica 



ha Shell sinistral B. perversum 



Ca Revolving canal at suture B. canaliculatum 



B. carica (L.). Shell thick, solid; spire 



conical, with a flattened surface and a 



revolving series of prominent tubercles 



above the suture; length 22 cm.; width 11 



,™.j.. cm. ; color gray or brownish : Cape Cod to 



-v^-v-^/:^I^^^B^■ll t^^® Crulf of Mexico, in shallow water; com- 



^^^^$^'^M mon, especially towards the south; the 



^"^^=j£m*{^ largest shell on the coast except Stromhus 



gigas. 



^'*^» B. canaliculatum (L.) (Fig. 880). Shell 



thin, covered with a hirsute periostracum, 



\'' \'MK and with a deep, broad canal at the suture; 



^, ^^^ „ ,. length 13 cm.; color brownish, with numer- 



Fig. 880 — Busycon canalicu- =" ' ' 



latum (Rogers). ous revolving lines: Cape Cod to Gulf of 



1, siphonal canal. ° ^ 



Mexico, in shallow water; very common. 



B. perversum (L.). Shell similar to B. carica, but sinistral: Cape 



Hatteras to Texas; West Indies. 



