THE APODOTJS HOLOTHURIANS 39 



firm, partially due to its being strongly contracted. The tentacles and internal 

 anatomy are not peculiar, but like those of any Caudina. The posterior pro- 

 longation of the radial pieces of the calcareous ring are only moderately long. 

 The calcareous particles in the body wall are cups closed by a cross, as in 

 coriacea and obesacauda, but very few of them are symmetrical and even these 

 are apparently without knobs. In fact, the vast majority of the cups are very 

 irregular and incomplete. 



Although this Caudina resembles both coriacea and obesacauda, the differ- 

 ences in the calcareous deposits, combined with the different shape of the 

 body and the geographical isolation of the species, are sufficient to warrant its 

 recognition. 



ETJPYRGUS SCABER Liitken. 



There is an excellent specimen of this interesting little species, from off 

 the coast of Alaska, "Albatross" Station 2852, 105 m. It agrees well with 

 typical specimens, and I think there can be no doubt of its specific identity. It 

 is of particular interest because the species has not been recorded hitherto from 

 west of Greenland, and its occurrence near Alaska would seem to indicate a cir- 

 cumpolar range. 



CERAPLECTANA, gen. nov. 

 (xepads, horny, + irAocTawu, feelers; in reference to the extraordinary tentacles.) 



Tentacles 10, simple, unbranched, horny, and pointed, provided with normal 

 ampullae. Body nearly cylindrical, but tapering posteriorly into a well-de- 

 veloped caudal appendage. Eadial pieces of calcareous ring with marked, but 

 not deeply forked, posterior prolongations. Calcareous deposits in the form 

 of irregular branched plates or straight rods, perforated near the middle, and- 

 usually with a single, sharp, outwardly directed spine. Phosphatic deposits 

 present. 



The type species of this genus is the following: 



CEHAPLECTANA TRACHYDERMA, sp. nov. 



(rpaxvi, rough, + Sep/ia, skin; in reference to the prickly body surface.) 

 PLATE XIII, FIGS. 5-13. 



Color gray, flecked with numerous patches of red brown. Tentacles 10, 

 almost the shape and color and nearly the size of apple seeds, arranged one 

 pair in each interradius. The ampullae are reasonably long. The respiratory 

 tree divides some distance from the cloaca, and the left branch is very short. 

 Deposits differ somewhat in different specimens. In the smallest the ellipses 

 are small, pale yellowish brown, and occur singly or in groups of three, while 

 the calcareous particles are fairly crowded, irregularly branched rods, flat and 



