I I 2 



i' similar t<> 1\, but shorter; first three or four pinnul< edingly 



long, extremely slender, stiff, composed of greatly elongated seg- 

 ments; aboul 40 arms: 37 39 cirrus segments of which the 

 eighth is a well marked transition segment; the outer cirrus 

 ;ments have .1 slightly produced distal edge and a median 

 nation ; the opposin^ spine is doublé, forming two thick lobes, 



one on either side of the median line Epimetra 



arms 

 e' th<- outer cirrus segments bear long and prominent dorsal spines, 

 which may be single or paired, and are shorter than the proximal 

 d 1 more than 35 cirrus segments of which the outer are much shorter 

 than the proximal, the latter being more or less elongated, and 

 bearing paired dorsal spines; pinnules long and very stiff, the 

 component segments with very spinous distal ends; proximal pin- 

 nules elongated, with greatly elongated segments; distal edges 



of the longer cirrus segments fringed with spines Colobometra 



d less than 35 cirrus segments of which the outer are but slightly 

 shorter than the proximal and bear single median dorsal spines ; 

 pinnules short and somewhat stiffened, the component segments 

 with spinous distal ends: proximal pinnules short, with short 

 segments; distal edges of the cirrus segments smooth .... Cotylometra 

 c- the outer cirrus segments bear a serrate transverse ridge dorsal ly, 

 and are as long as, or slightly longer than, the proximal 

 d 1 P, resembling P s , and of about the same length 



e 1 25 or more cirrus segments, all of which are broader than 

 long . the segments of the long and stiff P, and 1\ have 



smooth distal edges Petasometra 



e : 23 or fewer cirrus segments, the third-sixth and following 

 about as long as broad; the segments of the long stiff lower 



pinnules have very spinous distal ends Prometra 



d a P, shorter, more slender, and weaker than P., 



e 1 most, <>r all, of the cirrus segments broader than long; 1' 

 (and P if enlarged) distally usually more or less flagellate; 

 no lateral processes and few or 110 spines on the edges of 



the segments of the lower pinnules Decametra 



all hut the basal cirrus segments about as long as broad; 

 enlarged proximal pinnules commonly spine-like, without a 

 llagellate tip, the distal edges of the segments hearing lateral 

 processes or long spin 

 f 1 enlarged lower pinnules with elongated segments which 



have very spinous distal ends Prometra 



