PLATE XLIX. 
Figs. 1-3. Polycarpa hassi, n. sp. 
Figs. 4-6. Polycarpa longisiphonica {?), Herdman. 
Figs. 7, 8. Styela pusilla, n. sp. 
Figs. 9, 10. Styela radicosa {?), Herdman. 
Figs. 11-13. dona aspera, n. sp. 
hrj. Longitudinal fold in branchial sac. 
i. 1. Internal longitudinal bars of bran- 
chial sac. 
p. Papillse on the internal longitudinal 
bars. 
sg. Stigmata. 
ir'. Large and small transverse vessels. 
Fig. 1. Polycarpa hassi ; natural size. 
Fig. 2. Part of branchial sac of Polycarpa bassi, seen from the inside ; magnified 
(S., 1 inch). 
Fig. 3. Dissection of Polycarpa bassi, showing branchial sac and course of alimentary 
canal ; natural size. 
Fig. 4. Polycarpa longisiphonica {f); natural size. 
Fig. 5. Part of the branchial sac of Polycarpa longisiphonica {?), seen from the inside ; 
magnified (S., 1 inch). 
Fig. 6. Part of the ectoderm of Polycarpa longisiphonica{f); highly magnified (S., ^ inch). 
Fig. 7. Styela pusilla; natural size. 
Fig. 8. Part of the branchial sac of Styela pusilla, seen from the inside ; magnified 
(S., 1 inch). 
Fig. 9. Styela radicosa {?), from right side ; natural size. 
Fig. 10. Part of the branchial sac of Styela radicosa {?), seen from inside; magnified 
(S., 1 inch). 
Fig. 11 . Ciona aspera; natural size. 
Fig. 12 . Ciona aspera, with test removed; slightly enlarged. 
Fig. 13. Part of the branchial sac of Ciona aspera, seen from the inside; magnified 
(S., 1 inch). 
