534 I. IK EDA : 



di.stril)utioii. I will designate these types Ijy the letters .1, i>', C, 

 and JJ. 



Type A (lig. 13). The larvje of this type were principally 

 coUeeted in Aburatsubo and belong in all pr<)bability to the species 

 Fhoronia ijiitml, wliich, as I have said, is fonnd in the same 

 locality. The body is comparatively short and thick, measnring 

 abont 1.-1.'3 mm. in total length. The larval tentacles of a fidl 

 üTown larva never exceed 1(3 in nnndjer. 



Type B (fig. 14). This is a larger form than the preceding 

 (al)ont 2-2.5 mvi. in length). The body and the intestinal canal 

 are long and slender. The fnll grown larva has abont 28 tenta- 

 cles which are mnch more slender than those of Type A. Pecnliar 

 to it is the sensory spot (.so.) sitnated jnst in front of the ganglion 

 {(/L). The larvae were fonnd in greatest abnndance near Kitsune- 

 saki, a point at the month of the inlet Moroiso. 



Type C. (figs. 1-3 a & l>). This type is distingnished from 

 all the others by several characteristic points. In size of body 

 it is intermediate between Types A and B (nsnally l.bmm. in 

 length). The body is relatively short and thick. The nnmber 

 of tentacles, so far as I know, ranges from 16 to 24. A pair of 

 flask-shaped glands [gld.) is fonnd one on either side of the 

 ganglion [gl.]. A pair of retractor mnscles {i'ct\) runs longi- 

 tudinally through the trunk cavity from the tentacular ring to the 

 apex of the anal cone. Compared with the first two types this is 

 much rarer. 



Type D (figs. 12 and IC). This is a rare form of which I 

 have obtained only seven specimens in all. It is enormously large 

 in comparison with the others (4.-5. mm. in total length Jind 

 1. mm. in width). The ]>reoral lobe is disproportionately small, 

 while the trunk is Ion-' waA thick. The tentacles are remarkably 



