POLYCLADS OF THE EAST COAST — PEARSE 69 



Preserved, stained, and mounted, the type measures 11.6 mm long 

 and 5.8 mm wide. The structures in the median line are the following 

 distances from the anterior end : Brain, 2,7 mm ; pharynx, 3.5-8.2 mm ; 

 mouth, 8.0 mm ; male genital bursa, 8.2-8.8 mm ; genital opening, 8.9 

 mm ; shell gland, 9.4 mm ; accessory uterine organs, 9.9 mm ; posterior 

 loop of vasa deferentia, 10.2 mm. The cerebral and tentacular eyes 

 are arranged in two pairs of lateral groups, about 15 in each ; about 

 350 marginal eyes extend along the sides from the anterior end about 

 halfway to the posterior end. 



The pharynx is folded into about 10 lobes and is rather narrow; 

 1.0 by 5.1 mm. Ten pairs of branched, lobate caeca arise from the 

 median stem of the enteron dorsal to the pharynx and extend to the 

 margins of the body. The mouth is ventral, just anterior to the pos- 

 terior border of the pharynx. 



Close behind the mouth the prostate gland and penis are enclosed 

 in a pyriform sheath with two to four lateral appendages. The coiled 

 vasa deferentia extend forward from the prostate gland close beside 

 the pharynx. At about the posterior third of the pharynx each gives 

 off a lateral branch, which coils posteriorly and fuses with the one 

 from the opposite side behind the accessory uterine organs. The va- 

 gina, behind the single genital pore, is surrounded by shell-gland fol- 

 licles. Two lateral, longitudinal uteri extend forward from the shell 

 gland along the sides of the pharynx. None of those available con- 

 tain eggs, and all taper gradually toward the anterior. Behind the 

 shell gland a slightly sinuous median duct connects with a pair of 

 transverse accessory uterine organs, which are usually curved ante- 

 riorly near their distal ends. Numerous ovaries and testes are dis- 

 tributed in a ring around the pharynx and genital ducts, leaving a 

 zone about O.T mm wide free about the margin. 



Type.—V. S. N. M. no. 20186, from Crooked Island Sound, Farm- 

 dale, Fla.; collected November 21, 1935, by A. S. Pearse. 



Remarks. — This species differs from Dlscocelis nmtahilis Verrill, 

 1873, in having the cerebral and tentacular eyes arranged in two pairs 

 of groups and in being colored with radiating light streaks and a 

 lighter median band. 



Family STYLOCHIDAE 

 Genus STYLOCHUS Ehrenberg 



STYLOCHUS INIMICUS Palombi 



FiGUEE 23 



Stylochus inimicus Palombi, 1931, p. 219. 



As Palombi has given a complete description of this species and 

 as I have published (1938) a paper on the general ecology of this 



