244 Scientific Proceedings, Royal Dublin Society. 



EXPLANATION OF PLATE. 



Fig. 

 1. — Pneumodermopsis oligocotyla, sp. n. 

 1 A. — The entire animal, ventral view, x 12. s = suckers. 

 1 b.— Eadula. x 230. 

 1 c. — Spines from jaw. x 230. 



1 r>. — Spines of hook-sac. x 230. 



2. — Spongeohranchaea polycotyla, sp. n. 



2 A. — The entire animal, ventral view (restored), x 4. n = nuchal tentacle ; 



p = posterior gill. 

 2 b. — Isolated teeth from radula, greatly enlarged. 

 2 c. — Types of jaw spines, greatly enlarged. 

 2 D. — Group of suckers (the largest not drawn), greatly enlarged. 



2 E. — Separate spines from the hook-sac, greatly enlarged. 

 3. — Glionopsis longecirrata, sp. n. 



3 A. — The entire animal, ventral view, x 14. r = radula ; h = hooks ; 



p = penis ; p. I. = posterior lobe to foot. 

 3 b. — Types of lateral teeth of radula. x 230. 



3 c— Median tooth of radula. x 150. 

 4. — Cephalobrachia Bonnevii, sp. n. 



4 A. — The entire animal, ventral view, x 14. r = radula ; h = hooks ; 



(j = gonad. 

 4 b. — A median and two lateral teeth from radula, greatly enlarged. 



4 c. — A spine from hook-sac, greatly enlarged. 

 5. — Thliptodon atlanticus, sp. n. 



5 A. — The entire animal, ventral view, x 6. 

 5 b.— Median tooth of radula. x 90. 



5 c. — Lateral tooth of radula. x 40. 



5 D. — Spines of hook-sac. x 26. 

 6. — Thliptodon rotundatus, sp. n. 



6 A. — The entire animal, ventral view, x 6. 

 6 B. — Median tooth of radula. x 230. 



6 c. — Lateral teeth of radula. x 150. 



