21 G K. MITSUKURI : STUDIES ON 



Botli Theel and Sluiter had imperfect specimens, and their 

 descriptions contain tlierefore several mistakes such as would 

 naturally be caused by imperfect materials. In fact, my own 

 preserved specimens show more points of agreement with the 

 descriptions than the fresh specimens do. Theel's description of 

 the genus runs as follows : — 



" Body very depressed, with an extension of the body- wall 

 round its anterior extremity, constituting a very large, broad, and 

 rather flat brim. Tentacles twenty (?). The dorsal surface with 

 small projections round the margin of the brim and with some 

 other very small processes on its ambulacra. Pedicels along the 

 sides and round the posterior extremity of the body." 



The figures (PI. VII., figs. 59 and 00) show that the body is 

 far from being depressed. In fact, it shows a considerable height, 

 the ventral sole being flat, and the dorsal surface being consider- 

 ably vaulted. What was made out by Theel to be a broad brim 

 around the anterior extremity of the body is not such at all. It 

 should rather be compared to the dorsal hood-like appendage 

 seen in Peniagom and alhed genera. The mouth is ventral, and 

 the large circular oral field is surrounded by 20 large aspidochirote 

 tentacles. From the anterior cud of the mouth-field, the dorsal 

 appendage stands up like a hood. It is composed of 12 — 14 

 large finger-like appendages enclosed in a common membrane, 

 but each appendage can be easily recognized from the outside, 

 and its peripheral end seems to project a little beyond the edge 

 of the membrane. The outermost epidermis covering the whole 

 body is extremely dehcate and is easily torn off in shreds. 

 Below it, there is a rather thick layer of jelly-like connective 

 tissue, which seems to fill up entirely the space between the 

 outer epidermis and the inner layer next to the peritoneum. The 



