66 PROCEEDINGS OF THE NATIONAL MUSEUM vol. toe 



Order POLYCLADIDA 



Suborder ACOTYLEA 



Section Craspedommata 



Family Discocelidae Laidlaw, 1903 



Definition: Craspedommata with eyes, apart from the marginal 

 band, limited to definite cerebral and tentacular clusters; tentacles 

 wanting or rudimentary; penis massive, muscular, lobulated, depending 

 vertically from the dorsal wall of the male antrum; penis edged with 

 numerous small prostatic apparatuses, which may also be present in 

 the antral wall; Lang's vesicle present, usually crescentic. 



Genus Discocelis Ehrenberg, 1832 



Thalamoplana Laidlaw, 1904, p. 132. 



Definition: Discocelidae without prostatic vesicle or antral 

 pockets occupied by a large prostatoid. 



Type species: Planaria lichenoides Mertens, 1832. 



Discocelis insularis, new species 



Figures l,a,b; 2,a,c 



Material: Two specimens of this species were taken by J. P. E. ., 

 Morrison at night, Sept. 2, 1952, in Raroia Atoll, Tuamotu Islands. 



Explanation of figures 



1, marginal eyes 



2, cerebral eye cluster 



3, tentacular eye cluster 



4, uteri 



5, pharynx 



6, male apparatus 



7, male gonopore 



8, Lang's vesicle 



9, sperm ducts 



10, seminal vesicle 



11, ejaculatory duct 



12, male antrum 



13, penis 



14, prostatic apparatuses 



15, muscular pocket 



16, female gonopore 



17, vagina 



18, cement glands 



19, entrance of oviduct into vagina 



20, duct of Lang's vesicle 



21, anterior horn of Lang's vesicle 



22, cerebro frontal eyes 



23, brain 



24, mouth 



25, prostatic vesicle 



26, prostatic duct 



27, spermiducal bulbs 



28, penis sheath 



29, penis papilla 



30, vaginal duct 



31, vaginal pore 



32, tentacles 



33, tubercles 



34, common sperm duct 



35, female antrum 



36, accessory prostatic vesicles 



37, cirrus sac 



38, teeth in cirrus sac 



39, copulatory bursa 



40, spermiducal vesicle inside bursa 



41, sucker 



