80 PROCEEDINGS OF THE NATIONAL MUSEUM vou 86 



arranged more or less in a circle, or in an irregular circular group; 

 not in horseshoe form with the opening directed posteriorly, as is 

 usually the case in H. inquiUnu (Wheeler). The cerebral lobes are 

 at the posterior end of the first quarter of the body. 



The enteron has about 12 lateral branches on each side. These are 

 subdivided and extend nearly to the margin of the body of all sides. 

 The mouth is slightly anterior to the center of the body. The 

 pharynx has about six irregular lobes on each side, and the basal 

 trunks of these are comparatively smooth. The genital openings 

 are in the median line about one-fifth of the length of the body from 

 the posterior end. The one for the female system is about 0.1 mm 

 behind that of the male. A pyriform seminal vesicle is present but 

 no separate prostate gland. The penis is armed with a stylet. 



Type. — U.S.N.M. no. 20189, from Thais foridana Conrad; col- 

 lected at St. Vincent Bar, Apalachicola Bay, Fla., October 14, 1935, 

 by A. S. Pearse. 



Remarks. — This polyclad was usually found on the sides of dishes 

 in which crushed Thau foridana -fioridana Conrad were allowed to 

 stand, but it was once taken from the sides of pails in which oyster 

 shells were standing and once from a dish of barnacles. All speci- 

 mens examined came from Apalachicola Bay, Fla. These have been 

 compared with specimens of Ho'plopluna inquilina (Wheeler) that 

 came from the shells of Busycon canalicuIatuTn Linnaeus at Woods 

 Hole, Mass. The present species differs from the specimens of that 

 in Massachusetts in its smaller size, in the arrangement and number 

 of the eyes, and in the character of the lateral pharyngeal lobes. 



Family PLANOCERIDAE 

 Genus PLANOCERA Blainville 



PLANOCERA NEBULOSA Girard 



Planocera nehulosa Girard, 1854, p. 367. 



The only specimens in the collection of the National Museum 

 carrying this species designation are two determined by the late 

 A. E. Verrill. These specimens properly belong to the genus 

 EuMylochus, where I have also referred to them (p. 73). As a mat- 

 ter of record and for convenience, I have included Girard's species 

 in the key to the polyclads of our eastern seaboard, p. 96. 



Family STYLOCHOCESTIDAE 



CONJUGUTERUS, new genus 



Body elongated ; at least six times as long as wide when extended ; 

 without marginal eyes, tentacles, or tentacular eye groups; pharynx 



