POLYCLADS OF THE EAST COAST — PEARSE 73 



EUSTYLOCHUS ELLIPTICUS (Girard) 



Planocera elliptica Girard, 1850, p. 251. 



In the collection of the National Museum there are five specimens 

 of this species collected on Cape Cod, Mass., in 1879 at low tide mark; 

 and a specimen from Newport, R. I., August 20, 1880. Although 

 these are in poor condition, they were'stained, mounted, and used for 

 comparison with specimens of the next two species. 



EUSTYLOCHUS species ? 



Two poorly preserved specimens in the National Museum collec- 

 tion, one (U.S.N.M. no. 15624) collected off Newport, R. I., Sep- 

 tember 2, 1880, the other (U.S.N.M. no. 14398) from Woods Hole, 

 Mass., September 19, 1882, both determined by A. E. Verrill as 

 Planocera nehulosus Girard, unquestionably belong to the genus 

 Eustylochus. They have anterior marginal eyes and contiguous 

 genital pores very close to the posterior end. These specimens prob- 

 ably should be identified with the preceding species, but until some- 

 one makes a careful study of the Eustylochi on the New England 

 coast, their status, because of their poor state of preservation, must 

 remain specifically uncertain. For that reason this questioned species 

 has not been included in the key on p. 94. 



EUSTYLOCHUS MERIDIANALIS, new species 

 FiGUBB 25 



Body elongate-elliptical; very flat; length of a specimen measured 

 while crawling and extended on January 9, 1936, 24.0 mm; width, 

 11.00 mm; another slender individual measured 20 by 5 mm when 

 crawling; sizes of large preserved specimens are given in the table 

 below. Tentacles in living specimen, slender, conical; with eyes 

 extending to distal sixth ; 0.6 mm long ; about a seventh of the length 

 of the body from the anterior end. Mouth, ventral and about in the 

 middle of the median line. Pharynx a little less than half as long 

 as the body ; with anterior, posterior, and about six lateral lobes. The 

 enteron has a median stem and eight or more branched caeca on each 

 side. Brain largely or wholly posterior to the bases of the tentacles. 

 Eyes vary with age in number and arrangement. The marginal eyes 

 are seldom distributed posteriorly beyond the anterior fifth or sixth 

 of body, but in a few individuals they may be. One individual only 

 1.8 mm long, which perhaps belongs to this species, has eyes all 

 around its body Seven large individuals show the following ar- 

 rangement of eyes : 



