74 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



B. Cotylea: Family — Euryleptid^. 

 25. Cycloporus papillosus, Lang. (PI. XIY, figs. 41, 44.) 

 Length 10 — 15 mm. Body fairly consistent, oval, 

 slightly narrowed in front, where it is continued into a 

 pair of short stmnpy tentacles. The dorsal sm^face is 

 typically produced into a number of small, usually brightly 

 coloured papillae which are quite superficial elevations and 

 do not involve the underlying alimentary canal . They are 

 absent in the variety laevigatus, and are replaced by pig- 

 ment-spots. The colour is very variable and the meaning 

 of this variability is discussed below. Peripheral clumps 

 of pigment occur on the margin. Eyes are present on 

 and round the bases of the tentacles, and apair of larger 

 groups are also present over the brain, (cephalic groups). 

 The mouth hes behind the brain and leads into a bell- 

 shaped pharynx which appears as a light area on the 

 dorsal surface. The long main-gut is median and gives 

 off 6—7 pairs of lateral branches. The male and female 

 genital aperture lie behind the mouth in the order named. 

 The sucker is subcentrally placed on the ventral surface 

 of this animal. 



The conditions under which Cycloporus is found appear 

 to point very forcibly to the conclusion that the colouring 

 is associated and probably correlated with that of the 

 substratum. Cycloporus is found often in pairs of similarly 

 coloured individuals, on the surface of sponges and com- 

 pound ascidians both in the littoral and deeper zones. 

 The general colour is frequently but not always that of the 

 particular ascidian (Leptoclinum durum, &c.) The main- 

 gut which is median with lateral branches, appears to 

 simulate lines separating off the coenobia, while the peri- 

 pheral pigment-spots resemble in detail the coloured and 

 expanded ends of the vessels of the ascidian test. This is 

 not all. The sucker with which the Cycloporus is provided. 



