18 Clark — Seventeen New East Indian Crinoids. 



The small species of the Antedonidse, of which this collection 

 contains a large number, are most instructive in showing the 

 very intimate connection between many genera and several 

 subfamilies which heretofore have been considered as quite dis- 

 tinct. In the final report a revision of this difficult group will 

 be included. 



Palfeocomatella gen. now 



Genotype. — Actinometra difficilis P. H. Carpenter, 1888. 



Diagnosis. — Post-radial structure as in the twenty armed species of 

 Comatula (C. rotatoria); proximal cirrus segments (except the basal) 

 elongated; outer cirrus segments short and bearing dorsal tubercles as in 

 Comatella ; centrodorsal large, discoidal, the cirrus sockets in one and a 

 partial second marginal row, but the second row, instead of alternating 

 irregularly with the first as in all the other genera of comasterids, is exactly 

 beneath the first so that the cirrus sockets are arranged in columns, five 

 to each radial area. 



Capillaster gracilicirra sp. now 



This new form is closely related to C. seniosa, from which it differs in 

 its longer and much more slender cirri which have proportionately much 

 longer segments. The cirri are xvn, 27-35 (usually nearer the latter I, 

 33 mm. long; the longer proximal segments are twice as long as broad, 

 slightly constricted centrally with swollen ends ; the shorter distal seg- 

 ments are about as long as broad; the tenth or eleventh is a transition 

 segment. 



The arms are from fifty-one to one hundred ten in number, 100 mm. to 

 140 mm. long. 



Type locality.—" Siboga" Station No. 320. 



Capillaster tenuicirra sp. now 



This new species is closely related to C. multiradiata, but is compara- 

 tively slender and delicate, with much longer and much more slender 

 cirri. The cirri are xn-xvi, 24-30, 25 mm. to 28 mm. long; the fifth 

 and sixth segments are the longest, twice as long as broad; the tenth or 

 eleventh and following are very slightly longer than broad, and some- 

 times bear two, a proximal and a distal, dorsal spines. The cirri taper 

 slightly to the middle of the sixth (transition) segment, being more slen- 

 der and highly polished from that point onward. The arms are from ten 

 to thirty (usually between fifteen and twenty-five) in number, 110 mm. to 

 130 nun. long. ■ 



Type locality.—" Siboga " Station No. 320. 



Cotnissia littoralis sp. nov. 



The centrodorsal is discoidal, the dorsal pole fiat, 2.5 mm. to 3 mm. in 

 diameter. 



The cirri are x\i-.\xn,M(i, 10 mm. to 11 mm. long; the first segment 



