148 PROCEEDINGS OF THE ACADEMY OP [i^Iarch, 



indicate such an origin. Sections show that they are merely projections 

 on transverse cuticularized ridges which encircle the inner wall of the' 

 organ. 



As usual the ovaries are dorsally placed, and the tubes leading from- 

 them join with the uteri which are well defined a short distance anterior 

 to the mouth. From this point they extend backward, fuse in the 

 midline and form a single duct which passes dorsally into the egg canal. 

 Distal to this last-named union the egg canal extends posteriorly for a 

 short distance and enlarges slightly to form the small accessory sac- 

 On the other hand the egg tube passes backward, enlarges slightly tO' 

 form the shell chamber, beyond which it becomes continuous with the 

 bursa copulatrix. This is a thick-walled, cone-shaped organ whose 

 inner walls are developed into well-defined rugoe almost cuticular in^ 

 appearance. 



The following brief description will serve to distinguish this species 

 from other knowm forms. 

 Planocera hawaiiensis sp. nov. 



Body tolerably consistent, broadly elliptical or circular. Length of 

 largest specimen 39 mm., width 33 mm. Color wholly lacking or 

 limited to faint, black blotches and streaks on dorsal surface. Nuchal 

 tentacles at end of first fourth of body length ; bases surrounded by 

 eyes about twice the size of those of the intermediate area, which form 

 two groups, the greater number in front of the brain. Five lateral 

 and one anterior intestinal branches which are united by frequent 

 anastomoses. Testes and uniting tubes form an anastomosing system. 

 Penis lined with three species of spines or hooks, several being of large 

 size. Bursa large, accessory sac relatively small. 

 Auau Channel, Hawaii (Station 3,876), 28-43 fathoms. 



Explanation of Plate XIV, 



Fig. 1. — Planocera hawaiiensis, ventral view showing digestive and reproductive' 



systems. 

 Fig. 2. — Dorsal nervous system. 



Fig. 3. — One of the spines of the penis (for position see fig. 5). 

 Fig. 4. — Tentacles, eyes and brain. 

 Fig. 5. — Central portion of the reproductive system. B, bursa copulatrix; G^ 



granular gland ; P, penis. 

 Fig. 6. — Large penis spine (for position see fig. 5). 



