182 



AMERICAN JOURNAL 



SYNOPSIS OF THE GENERA SYCOTYPUS, BROWNE, AND 

 BUSYCON, BOLTEN. 



BY T. A, CONRAD. 



The name of Sycotypus is applied to the genus Ficus, Klein, 

 (Ficida, Swainson,) by Adams and Hermannsen on the authority 

 of Gronovius, who quotes it with a mark of doubt. There is no 

 shell of the West Indies that answers to the simple designation 

 of "smaller hairy fig shell, lightly tuberculated," but it is very 

 probable that the shell known as Bulla canaliculata, Lin., was 

 in the collections in Jamaica, and regarded as a native. The 

 description does not apply to any species of Ficus, for the sim- 

 ple designation " hairy " would alone distinguish Browne's 

 genus from Ficus. We have no knowledge of any anatomical 

 characters by which to separate this genus from Busycon, 

 Bolten, which was founded on Murex aruanus, Lin., but as the 

 two groups have very characteristic differences in the shells, one 

 being spinous and the other channelled and tuberculated, the 

 one having reversed species, the other never reversed, it is most 

 convenient to regard them as distinct genera, especially as the 

 embryo in the egg pouches of B. aruanum have a long fissure, 

 parallel with the columella, Avhich exhibits the interior to the 

 apex, and the embryo of S. canaliculatus is always entire. I 

 do not think the partial union of the characters of the two 

 groups, as represented by the Miocene fossils, should decide us ' 

 to retain the whole group under one generic term ; for, otherwise, 

 very many recent genera would have to be eliminated for the 

 same reason. But it is remarkable that this trenchant distinc- 

 tion between Sycotypus and Busycon should have taken place 

 so soon after the Miocene period, in which several species of 

 shells can scarcely be distinguished from living shells of the 

 coast. 



