GASTROPODA 



559 



N. decemcostata (Say). Shell with 6 whorls, 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. 



capsules of Busycon canaliculatum 

 (Rogers). 



FAMILY 5. TUKBINELLIDAE. 



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. BTJSYCON Bolton (Fulgur Montfort). Conchs. Shell large, with 

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

 long twisted canal; 

 aperture large ; outer 

 lip thin and smooth; 

 whorls 6: 5 species on 

 the eastern coast of Fig. 879 Egg 

 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: 



a t No sutural canal. 



&x Shell dextral B. CABICA 



6 3 Shell sinistral B. PEBVERSUM 



a. 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 

 cm.; color gray or brownish: Cape Cod to 

 the Gulf of Mexico, in shallow water; com- 

 mon, especially towards the south; the 

 largest shell on the coast except Strombus 

 gigas. 



B. canaliculatum (L.) (Fig. 880). Shell 

 thin, covered with a hirsute periostracurn, 

 and with a deep, broad canal at the suture; 

 length 13 cm.; color brownish, with numer- 

 ous revolving lines: Cape Cod to Gulf of 

 Mexico, in shallow water; very common. 

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

 Hatteras to Texas; West Indies. 



Fig. 880 Busycon canalicu- 

 latum (Rogers). 

 1, siphonal canal. 



