THE APODOUS HOLOTHURIANS 33 



MOLPADIA ARENICOLA (StimpSOn). 



PLATE XII, FIGS. 1,' 2. 



There are 8 specimens of this species in the collection, and they agree per- 

 fectly with Stimpson's description, except that the calcareous ring consists of 

 the usual 10 pieces found in the Molpadiidae. The largest is about 120 mm. 

 long and 35 mm. in diameter, and the caudal portion is not abruptly narrowed, 

 though it is only 5 mm. thick at the extremity; although there are no deposits 

 in the skin of the body, there are numerous small, much-branched rods and per- 

 forated plates in the skin of the tail. In the smallest specimens, the calca- 

 reous particles are more abundant. The specimens are from San Pedro and 

 San Diego, California, and "Southern California." Some, if not all, were 

 picked up on the beach after storms. 



MOLPADIA BLAKEI (Theel). 



There is a single specimen of this very well characterized form, from 

 "Albatross" Station 2383, Gulf of Mexico, lat. 28 32' N. and long. 88 6' W., 

 2,126 m. It is of a light grayish-brown color and about 50 mm. long. The cau- 

 dal appendage is very short, there are no colored bodies, and the remarkable 

 tables are very abundant, though not crowded. 



MOLPADIA GBANULATA (Ludwig). 



Ludwig's type and three co-types, from "Albatross" Stations 3361 and 

 3399, off Panama, 2,648-3,132 m., are in the collection, but there are no other 

 specimens. 



MOLPADIA INTERMEDIA (Ludwig). 

 PLATE XII, PIGS. 5-15. 



This is apparently the common Molpadia of the eastern Pacific, for there 

 are no less than 143 specimens before me, collected at various points from the 

 28th to the 56th parallel, and at depths ranging from 52 to 2,925 m. They 

 vary in length from 17 to 105 mm., with corresponding variety in form, texture 

 of skin, and color. The smallest specimens are gray, and the yellowish-brown 

 ellipses in the skin are so small and scattered they only become visible under the 

 microscope ; the skin is very thin and delicate and abundantly supplied with cal- 

 careous bodies, the tables characteristic of the species, and the rosettes and 

 anchors supposedly characteristic of Ankyroderma. The largest specimens 

 have the ground color gray, but this is more or less completely hidden by the 

 reddish-brown color, caused by the very numerous ' ' ellipses ' ' ; the skin is mod- 

 erately thin but firm; the calcareous bodies are in nearly all cases simply the 

 tables, but not infrequently the last browning remnants of a rosette are found, 

 and occasionally more or less complete rosettes and anchors occur. Between 



