498 P. W. GAMBLE. 



the female pore a short distance behind this. The penis is 

 pyriform, and receives the contents ofavesicula seminal is 

 and granule-gland. The uterus lies in front and at the 

 sides of the pharynx ; it opens to the exterior along with 

 the spermotheca through the vagina. 



Habitat. — Berwick Bay (Johnston); Firth of Forth (Dal- 

 yell); Firman Bay, Guernsey (Lankester) ; St. Andrews 

 (Mcintosh) ; Jersey (Koehler). 



Distribution. — St. Malo (Quatrefages), St. Vaaste-la- 

 Hogue (Claparede). 



Family LEPTOPLANID^. 



Mouth and pharynx subcentral. Main-gut usually 

 extends in front of, rarely behind, the pharyngeal 

 sheath. Branches numerous. Male copulatory 

 organ directed posteriorly. Tentacles absent. 

 "Eyes — (1) two lateral groups on the areas repre- 

 senting the tentacles of Planoceridse ; (2) double 

 cephalic group; (3) marginal; (4) irregularly dis- 

 posed over the head. Direct development. 



Genus 29. — Leptoplana, Ehrenberg (10). 



Leptoplanidse with elongate, delicate body. Pharyn- 

 geal sheath long. Lateral pouches numerous. 

 Pharynx not completely folded. Genital aper- 

 tures distinct. Granule-gland and vesicula semi- 

 nalis separate. Marginal eyes absent. Eyes of 

 group (1) larger than those of (2). 



62. Leptoplana tremellaris (O. F. Miiller). 



1774. Fasciola tremellaris, 0. F. Miiller (2). 



1776. 1'lanaria tremellaris, O. F. Miiller (4). 

 1814. „ FLEXiLis, Dalyell (6). 



1840. „ TREMELLARIS, W. Thompson (15). 



1844. Leptoplana TREMELLARIS, Oersted (16j. 



1845. Planaria flexilis, Johns tou (20). 



