PLATE XII. 



Fig. 1. Bifurcating pinnule of Hathrometra prolixa (Сотр. Fig.l). ^/i. 



— 2. Stalk joint of Pentacrinoid larva of Hathrometra prolixa, seen 



from above (Comp. Fig. 3). ^^-'h. 



— 3. Upper part of stalk joint of Pentacrinoid larva of Hathro- 



metra prolixa, side view (Comp. Fig. 2). ^^'"Ii. 



— 4. Arm joints of Pentacrinoid larva of Hathrometra prolixa, 



stage IV. Tentacles omitted. *^''/i. 



— 5. Part of calyx of Pentacrinoid larva of Hathrometra prolixa, 



showing in the middle, where the oralia (o) and basalia (b) 

 meet, the radial I and the anal plate; outside the radial I 

 the first beginning of radial II is seen. ^^'/i. 



— 6. Stalk joints, from the middle of the stalk, of the Pentacrinoid 



larva of Heliometra glacialis. *^''h. 



— 7. Proximal part of bifurcating pinnule of Hathrometra prolixa 



(Comp. Fig. 1). ''''I и 



— 8. Stalk joints, from the middle of the stalk, of the Pentacrinoid 



larva of Antedon petasiis. ^"-Vi. 



