THE CEPHYREA OE JAPAN. 25 



total length 22 irwi., of which about 1/3 mm. appertain to the 

 introvert. The number of longitudinal muscles in the anterior 

 half of the body proper, is on an average 14, while in the posterior 

 half each longitudinal muscle divides twice successively before 

 reaching the posterior end of the body. The tentacles, filamentous 

 in form and about 30 in number, are arranged in one row, 

 ventrally and laterally to the mouth. Each tentacle bears in the 

 fresh state, as was mentioned by Keferstein, two narrow band- 

 like marking's of a bluish black color. 



The anus and the external apertures of the segmental organs 

 lie at the same level ; the latter perforate the body-wall between 

 the second and the third longitudinal muscles. The roots of the two 

 retractor muscles spring from the 2nd-4th longitudinal muscles. 

 Eectal diverticulum is not present. Two distinct eye-spots are 

 found on the ganglion. 



Specimens are obtained by breaking coral rocks. 



PHYMOSOMA PACIFICUM, Keferstein. 



Selenka, (28), 1883, ^j». 63. 



The main features of the species as embodied in Selenka's 

 description are as follows : — 



Body proper, 8 cm. in length and 14 mm. in maximum 

 breadth. Introvert longer than bod}^ proper, so that the whole 

 length may reach 29 cm. Color grayish, blackish, or reddish 

 brown ; often with small black specks ; introvert generally bears 

 on the dorsal side irregular pigmented bands. Body-wall thick. 



