REPORT ON THE ALCYONARIA. 27 



forms of Ceratoisis. It is, therefore, thought desiral^le to emend the characters of 

 the latter genus, so as to admit all the uubrauched forms with hollow stems of Isidas. 

 It is of course possible that with increasing knowledge this genus wiU have to be 

 subdivided. Unfortunately very few specimens of the species of this group were 

 collected during the voyage of the Expedition, so that even the specific characters are 

 not in many cases as satisfactorily determined as could be wished. It is somewhat 

 remarkable that aU the species found belong to the unbranchcd division of the genus. 



1. Ceratoisis philipinnensis, n. sp. (PI. Va. fig. 5). 



Axis uubrauched. Calcareous internodes very slightly grooved, somewhat irregular 

 and knobbed, 3 to 4 cm. long, 5 mm. in diameter, but tapering to the thinness of a 

 hair from a horse's tail, apical portion hollow. Nodal regions 5 mm. high, ccenenchyma 

 thick and membranous, covered with both fusiform and lenticular spicules. 



Polyps prominent, in irregular verticils rather closely packed on the axis, with 

 tentacles retracted, 6 mm. in height, covered with fusiform spicules, six or eight of which 

 form a calyx around the base of the retracted tentacles. 



This species is very closely related to Ceratoisis grayi, but difi"ers from it in its mode 

 of growth, in the greater abundance in the ccenenchyma of the lenticular spicules, and in 

 the spicules of the polyps. Six or seven fragments of from 15 to 20 cm. in height, and 

 aU apparently forming portions of the same axis, but without a basal portion, were 

 taken at the Philippines. 



Spicules in the ccenenchyma, lenticular, sometimes asymmetrical ; in the polyps, 

 fusiform, with papilliform endings, sometimes broad, at other times narrow. 



The large spicules around the base of the tentacles measure l'2-0"08 ; 1-0"01 ; 2"5-0"l ; 

 r2-0-l mm. The lenticular spicules measure 0-87-0-05 ; 0-2-0-58 ; 0-25-0-057 mm. 



Habitat. — Station 201, oif the Philippines; depth, 82 fathoms; bottom, stones, 

 gravel. 



2. Ceratoisis grandijlora, Studer (PL Va. fig. 6). 



Ceratoisis grandiflora, Studer, I\Iouatsber. d. k. prcuss. Akad. d. Wiss. Berlin, 1878, p. G62, 



Axis uubrauched ; base disc-like, affixed to rocks ; calcareous internodes, varying 

 greatly in length, from 1-5 to 5 cm., the shortest near the base, solid towards base, hollow 

 towards apex. Polyps very large, placed on the axis in an ii-regularly alternate manner. 

 Ccenenchyma thin, membranous, covered with lenticular spicules, which also cover the 

 greater portion of the base of the polyps. Tentacles very imperfectly retractile ; six 

 to eight spine-like spicules, with irregular bifid tips, surround the base of the 

 tentacles. 



