PLATE XL, 



EXPLANATION. 



Fig. 



1. Vaginicola crystallina, Ehr., vol. ii. p. 7 1 5. — Lorica containing two zooids, 



X 200. 



2. Stylocola striata, From., vol. ii. p. 730, x 300 (De Fromentel). 



3. Vaginicola globosa, D'Udk., vol. ii. p. 716, dimensions unrecorded (D'Udekem). 

 4, 5. Thuricola VALVATA, Wright sp., vol. ii. p. 718.— Loricae with two zooids in an 



expanded and contracted state ; v, valvular structure, x 200 (Str. Wright). 



6-8. Thuricola folliculata, MUU. sp., vol. ii. p. 718.— 6, Fully extended zooid 

 with at ■^/^' lateral edges of pectinate valve, x 200; 7 and 8, distal region 

 of lorica showing pectinate structure of valve, x 400. 



9, 10. Cothurnia imberbis, Ehr., vol. ii. p. 720. — 9, Lorica containing two zooids, 

 that at « in a contracted condition, having developed a subcentral ciliary 

 girdle preparatory to migration, X 200; 10, detached migratory zooid (Greefif). 



11. Cothurnia pontica, Meresch.,vol. ii. p. 725. — Empty lorica, x i5o(Meresch- 



kowsky). 



12. Cothurnia gracilis, S. K., vol. ii. p. 724. — Zooid contracted, x 250. 



13-15. Thuricola operculata, Gruber sp., vol. ii. p. 719. — 13 and 14, Expanded zooids, 

 showing at op valve-like operculum, and at / retractile ligament that connects 

 the same with the body at the bottom of the lorica ; 15, basal region with the 

 operculum and retractile ligament diagrammatically represented (Gruber). 



16. Pyxicola socialis, Gruber sp., vol. ii. p. 728. — Distal region of expanded zooid 

 with at m collar-like membrane, dimensions unrecorded (Gruber). 



\'], 18. Cothurnia compressa, C. & L., vol. ii. p. 722. — Front and lateral aspects, 

 X 170 (Claparfede & Lachmann). 



19. Cothurnia havniensis, Ehr., vol. ii. p. 720, x 100 (Ehrenberg). 



20, 21. Cothurnia patula, From., vol. ii. p. 722. — Lorica with two zooids in their 

 expanded and contracted states, x 200 (De Fromentel). 



22. Cothurnia Cohnii, S. K., vol. ii. p. 723, x 400 (Cohn). 



23. Cothurnia pupa, Eichw., vol. ii. p. 724, dimensions unrecorded (Eichwald). 



24, 25. Cothurnia Sieboldii, Stein, vol. ii. p. 720. — Ventral and lateral aspects, x 150 

 (Stein). 



26. Cothurnia astaci, Stein, vol. ii. p. 721, x 150 (Stein). 



27. Cothurnia curva, Stein, vol. ii. p. 721, x 300 (Stein). 



