1888.] NATURAL SCIENCES OF PHILADELPHIA. 311 



West Indies — but on this point I can offer no satisfactory evidence, 

 never having had an opportunity to examine authentic specimens of 

 Jiiger's species. 



Holothuria captiva, Ludwi^. (PI. 14, figs. 4, 4a) 



Two individuals, agreeing with the species described by Ludwig 

 from the Barbados. 



Holothuria abbreviata, n. sp. (PI. 14, figs. 5, 8, 8a.) 



Among the smaller forms of holothurians is one which in many 

 of its characters agrees most closely with Ludwig's H. captiva, but 

 yet differs to such an extent as to compel me to recognize it as a 

 distinct species. Indeed, by many systematists it would probably be 

 made the type of a distinct sub-genus or genus. The distinguishing 

 peculiarity is the abrupt truncation of the body, which carries the 

 vent on the dorsal surfoce, immediately 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 14. It will be seen that in general they bear a close 

 resemblance to those o? Holothuria captiva, but the rounded sum- 

 mits of the stools serve readily to distinguish them from the some- 

 what similar, but more strictly castellated, bodies of the other spe- 

 cies. 



SEMPEKIA. 

 Semperia Bermudensis, n. sp. (PI. 14, figs. 2, 2a, 3.) 



Body cylindrical, spindle-shaped, tapering almost equally to both 

 extremities. Tentacles 10, of which 4 are shorter than the remain- 

 ing 6 ; pedicels crowded, arranged in five broad rows, and scattered 

 over the interambulacral areas ; two genital bundles, with very 

 numerous non-divided, and greatly elongated filaments ; two Polian 

 vesicles ; two long respiratory trees. Color greyish white, minutely 

 speckled with brown ; five narrow longitudinal brown bands sepa- 

 rating the ambulacral areas. Length about 05 inches. 



Calcareous bodies consisting of baskets, knotted and smooth but- 

 tons, and perforated more or less circular disks ; pedicels with fen- 

 estrated plates. Calcareous ring with long back processes for the 

 attachment of the powerful retracted muscles. 



