Bd. VI: 8) 



THE CRINOIDEA. 



II 



twice as broad as long; the distal edge concave, for the reception of the axillar)-, 

 which is also very broad, '/a broader than long. The costals are in apposition laterally, 

 at least in their lower part. Both the primibrachs and the lower brachialia are flat- 

 tened, with sharp side-edges. The distal edge of the outer brachials is smooth, but 

 somewhat thickened, giving the arms a serrate appearance (Figs. 8 a — c). 



Syzygies numerous; the first two constantly on the 3rd and 8th joint (the syzy- 

 gial joint counted as one); from the second syzygy on there is mostly two or three 



Fig. 6. Centrodorsal and basal 



part of arm of Isometra vivi- 



para. ',i. 



Fig. 7. Cirrus of ho- 

 rn it ra vivipara. ^ji. 



a. b. c. 



Fig. 8. a. Dorsal view of arm joints from the 



middle of the arm; b. side view of the same: 



c. dorsal view of ami joints from distal part 



of the arm of homitra ■vivipara. "/i. 



joints between the syzygies, but sometimes only one, or there may be as many as 

 four or, rarely, five. 



The oral pinnules (Fig. 9) are ca. 6 — 7 mm long, in grown specimens, P| only 

 slightly longer than P2-3. They are fairly robust, with 12 — 14 short, smooth joints 

 and without a terminal comb. P3 generally has the ambulacral furrow developed. P4 

 has a slight widening of the 3rd and 4th joint; Pj is a fully developed genital pinnule. 

 The genital pinnules are ca. 9 mm. long, the distal pinnules slightly shorter and some- 

 what more slender. 



