300 



In the polian vesicles there are numerous calcareous deposits (Fig. 

 62. 5) of varying shape. 



Chiridota pisanii Ludwig differs, as seen from the description, not 

 only distinctly from Ch. Icevis, but it is not more closely related to 

 any of the species hitherto known. 



Chiridota hawaiiensis Fisher. 

 Chiridota hawaiiensis. Fisher. 1907. Hawaiian Holothurians. pag. 731, 



PI. 81 fig. 5, PI. 82 fig. 3 a— c. 

 Chiridota rigida partim. Clark. 1908. The Apodous Holothurians. p. 117. 

 Hilo, Hawaii. IV. 1915. 14 specimens. 

 Honolulu. I.V. 1915. 18 specimens. 



There can in my opinion be no doubt that the specimens at 

 hand are identical with Fisher's species Chiridota hawaiiensis. 

 Clark unites in "The Apod. Holoth." this species with Semper's 

 rigida, but the examination of the specimens at hand shows that 

 they are evidently specifically different from that species. 



The specimens at hand are rather small, not measuring more 

 than 3 — 3,5 cm in length. They are in alcohol pale reddish-brown 

 or nearly colourless, and the colour of the tentacles is not as in 

 rigida different from that of the body. The body-wall is very thin 

 and nearly quite translucent. The wheel-papillae are of varying size 

 and not equally distributed. They are very crowded on the anterior 

 end of the dorsal side and nearly wanting in the posterior end. There 

 are twelve tentacles, each with 3 — 5 pairs of digits. The two terminal 

 digits are by far the longest, and in some of the specimens they 

 may be united unto their end. 



The calcareous ring consists of twelve pieces of which the two 

 extra interradiais are found in the dorso-lateral interradii, one in 

 each. The two dorsal radiais (Fig. 62. 10) are perforated for the 

 nerves and distinctly different from the three ventral radiais, which 

 are but notched in the anterior margin. Also in the shape of the 

 posterior margin the radiais may be different, that of the mid-ven- 

 tral and usually, but not constantly, also that of the two latero- 

 ventral radiais having a double notch (Fig. 62. 11). The mid-dorsal 

 interradial differs from the others, especially from the two ventral 

 ones in having a conspicuous projection on the exterior side. A 

 cartilaginous ring is wanting. There are 9 — 11 polian vesicles, the 



