240 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



The two specimens upon which this species is based are among the most ex- 

 traordinary unstalked crinoids I have ever seen ; that they are adult is shown by 

 the great enlargement of the genital glands, which contain ova ; but all the other 

 characters, the prominent basals, long radials, costals, and brachials, and rudimen- 

 tary lower pinnules, and the few cirrus joints, are clearly juvenile, and in general 

 the specimens appear to be much less developed than some of the very large H. 

 hondoensis, which are less than half their size. 



Psathyrometra, sp. 



Some fragments of arms from "Albatross " Station No. 2818, 0° 29' 00" south 

 latitude, 89° 54' 30" west longitude (Galapagos Islands), belong to a species of 

 this genus, possibly P. bigradata, whicli has been found in the Galapagos group. 

 The specimen was taken iu 392 fathoms on a bottom of black and white sand, the 

 bottom temperature being 43.9° P. The Galapagos specimen of P. bigradata was 

 found in 385 fathoms, at a temperature of 43.2° F. 



This is the first record for the arms of any species of the genus, outside of the 

 Bering Sea and Sea of Japan, where fairly good specimens have been obtained. 

 Dr. Hartlaub's examples all lacked the arms beyond the syzygy in the third 

 brachial, and this is the condition in which species of this genus are usually re- 

 covered, as is the case with the closely allied Zenometra of the Caribbean Sea. 



Antedon serrata, sp. nov. 



Centro-dorsal low-hemispherical, bearing about thirty cirri ; these are 7 mm. or 

 8 mm. long, and consist of eleven to fourteen segments, the first two short, the 

 others rather longer than wide ; the proximal half are more or less " dice-box " 

 shaped ; opposing spine minute; radials just visible as small interradial triangles; 

 first costals very short ; axillaries triangular, about twice as wide as high ; ten 

 arms 45 mm. long ; first two brachials wedge shaped, the longer side out ; third 

 brachial wedge shaped, the longer side in ; next three brachials oblong, then 

 becoming quadrate, at first short, but after the eleventh about as long as wide, 

 and elongate after the middle of the arm ; syzygia occur in the third, eighth, and 

 twelfth brachials, and distally at intervals of two ; first pinnule 5 mm. long, com- 

 posed of fifteen segments, the first very short, the second rather longer than broad, 

 then becoming elongated ; the ends of the segments are turned outward and pro- 

 duced dorsally, and armed with very fine spines ; the five following pinnules are 

 similar to the first, but considerably shorter, with the distal eversion of the pinnule 

 segments more marked, the dorsal projection equal to from one half to nearly the 

 whole length of the segment; the remaining pinnules become more slender, and 

 the projection of the distal end of the pinnule segments gradually dies away. 



Color (in spirits) brownish, the arms narrowly banded on about every third 

 brachial with darker. 



