138 THE BERMUDA ISLANDS. 



genus. The distinguishing pecuHarity is the abrupt truncation 

 of the body, which carries the vent on the dorsal surface, im- 

 mediately about the extremital border. In the single specimen 

 before me I could determine only 17 tentacles, with as many 

 tentacular vesicles, and but a single Polian body. A large 

 Cuvierian bundle is present. The pedicels are arranged ven- 

 trally in three more or less distinct rows. Color olive green. 

 Length about two inches. 



The stools, buttons, and fenestrated plates of the pedicels are 

 figured on plate 12. It will be seen that in general they bear 

 a close resemblance to those of IJolothuria captiva, but the 

 rounded summits of the stools serve readily to distinguish 

 them from the somewhat similar, but more strictly castellated, 

 bodies of the other species. 



SEUFEBIA. 

 Semperia BeTmudensiB, u. sp. (PI. 12, figs. 2, 2a, 3.) 



Body cylindrical, spindle-shaped, tapering almost equally to 

 both extremities. Tentacles 10, of which four are shorter than 

 the remaining 6 ; pedicels crowded, arranged in five broad 

 rows, and scattered over the interambulacral areas ; two genital 

 bundles, with very numerous non-divided, and greatly elon- 

 gated filaments; two Polian vesicles; two long respiratory 

 trees. Color grayish white, minutely speckled with brown; 

 five narrow longitudinal brown bands separating the ambulac- 

 ral areas. Length about 3J inches. 



Calcareous bodies consisting of baskets, knotted and smooth 

 buttons, and perforated more or less circular disks ; pedicels 

 with fenestrated plates. Calcareous ring with long back proc- 

 esses for the attachment of the powerful retractor muscles. 



One specimen, from the north shore about a half-mile west 

 of Flatts Village. 



I first mistook this species for the Semperia (Colochirus) gem- 

 mata of Pourtalfes (Proc. Amer. Assoc. 1851, p. 11), described 

 from Sullivan's Island, coast of South Carolina, but the more 

 exact descriptions and figures of that species given by Selenka 

 and Lampert convince me that it is quite distinct. Both 



