458 PROCEEDINGS OF THE ACADEMY OF [Sept., 



bb. ( ommon sex opening. 



c. Tentacle eyes small, numerous; cerebral eyes 



minute, converging anteriorly L. californica. 



cc. Tentacle eyes large, few; cerebral eyes not con- 

 verging L. inquieta. 



aa. A pair of seminal vesicles Phylloplana litoricola. 



II. With sucking disc on ventral surface Tribe Cotylea. 



A. Numerous gut branches; tentacles appear as marginal folds; 



pharynx folded Family Pseudocerid^e. 



a. Approximately 50 pairs of gut branches, 



Lichenoplana lepida. 

 AA. Few gut branches; solid marginal tentacles; pharynx without 



folds Family Euryleptid^e. 



a. Mouth and male sex opening a common aperture; female 

 pore before hind end of pharynx, 



Stylostomum calif ornicvm. 



aa. Mouth and male aperture not united; female opening 



behind posterior end of pharynx. 



b. Mouth immediately behind the brain which is close to 



the anterior body margin; male aperture under 



.front end of pharyngeal pocket; tentacles lacking, 



Acer os langi. 



bb. Mouth well removed from brain and body margin; 



male aperture behind pharyngeal pocket or ventral 



to posterior end of it; tentacles usually present. 



c. Eyes lacking in region of tentacles; vasa deferentia 



and uteri anastomosed; no uterus glands, 



Anciliplana graffi. 

 cc. Eyes present in tentacle region. 



d. A pair of uterus glands present; gut branches 

 and vasa deferentia not anastomosing, 



Eurylepta aurantiaca. 

 dd. Uterus glands wanting; gut branches anas- 

 tomosed Genus Euryleptodes. 



e. Granular gland present; vasa deferentia 

 unbranched. 



f. Tentacles well developed E. cavicola. 



ff. Tentacles absent or rudimentary, 1 



E. panmdus. 



ee. Granular gland absent; vasa deferentia 



elaborately anastomosed E. phyllvlus. 



Tribus ACOTYLEA. 



Without sucking disc. Mouth in middle of the body or behind it. 

 Pharynx ruff-like. Copulatory apparatus in the posterior end of 

 the body. Without tentacles or with nuchal tentacles. 



1 Cf. page 485. 



