BATHYMETRINAE 169 



ossicles of the division series and the lower brachials are more massive and conspicuously 

 wider than in the female (Fig. 10 ?). The cirri are longer. These may perhaps be signs of 

 greater age. 



In two specimens P3 is the first genital, in the other P., . The following are the numbers 

 of segments and the lengths of some pinnules : 



First specimen: Pj 20 segments 5 mm. 



Second specimen: Pj, the first genital pinnule 12 segments 4 mm. 



Third specimen: Pj 19 segments 6 mm. 



Pa 16 segments 5 mm. 



P3 , first genital pinnule — none complete ; but 

 Pc II segments 3-5 mm. 



The testes are long fusiform bodies, the biggest lying along the third to eighth seg- 

 ments of the genital pinnules. 



The disk is naked, the anal cone very high. 



Phrixometra longipinna (P. H. Carpenter) 



Antedon longipinna Carpenter, 1888, p. 185, pi. xxx, figs. 1-3. 

 Phrixometra longipinna A. H. Clark, 1917, p. 131. 



Carpenter described this species from "three mutilated individuals" taken by the 

 ' Challenger ' from 600 fathoms off the River Plate. It has not been recorded since. 

 I have re-examined the type specimens. 



The centrodorsal is a straight-sided or rounded cone with a greater diameter than 

 height. The cirrus sockets are in fifteen regular or slightly irregular columns. Carpenter 

 describes the cirri as being about 30 in number, of 20-25 segments. Only two cirri are 

 now left, one incomplete of 20 segments, one complete of 19. They differ from those of 

 the var. antarctica, as Carpenter's fig. 3, which is a good picture, shows. The longest 

 segments are only just more than twice as long as broad. The distal segments are not 

 strongly compressed : they are not broader than the more elongated middle segments, 

 so that the end of the cirrus does not appear heavier than the middle. 



The ossicles of the division series and the brachials are very like those of the var. 

 antarctica, as a comparison of Carpenter's figures and mine will show. The distal edges 

 of the outer brachials are strongly thorny. 



Carpenter's description of the pinnules is misleading. He states that those following 

 the first two pairs are "all long, decreasing but slowly in size", whereas the most 

 conspicuous feature of the pinnules is, as in the var. antarctica, a sharp contrast in the 

 number of the segments and the lengths between the orals and the genitals. ^ The con- 

 trast is far stronger than in either of the specimens of the var. antarctica : the oral pinnules 

 reach much farther along the arms. Their elongated segments, beyond the third, are 

 four to six times as long as broad. 



1 Clark {loc. cit.) in his diagnosis of Phrixometra repeats the error in other terms, saying that the pinnules 

 following the orals are similar to them. 



