450 PROCEEDINGS OF THE NATIONAL MUSEUM vol.89 



The polyclads of the Sa^gasswm are omitted here, as they are 

 considered in full elsewhere (Hyman, 1939b). 



Order POLYCLADIDA 

 Suborder ACOTYLEA ' 



Defmition. — Polyclads without a sucker behind the female genital 

 pore ; tentacles when present of the nuchal type ; eyes never in paired 

 groups on the anterior margin ; pharynx typically ruffled ; copulatory 

 complex generally in the posterior body half; uteri extending an- 

 terior to the female genital pore (but in a few families the pharynx is 

 tubular and the copulatory complex may then be in the anterior half) . 



Section Craspedommata Bock, 1913 



De-fmition. — Acotylea with a band of eyes along the whole or the 

 anterior part of the body margin; with cerebral and tentacular eye 

 clusters in addition and sometimes also frontal eyes, or anterior end 

 strewn with small eyes not arranged in clusters (eyes completely lack- 

 ing in Plehnia arctica) . 



Family DISCOCELIDAE Laidlaw, 1903 



Definition. — Craspedommata of oval form with marginal band of 

 eyes limited to the anterior body half ; tentacles absent ; cerebral and 

 tentacular eye clusters present; copulatory complex immediately be- 

 hind the pharynx ; male organ and wall of male antrum with numerous 

 prostatic apparatuses ; typical prostatic vesicle absent. 



CORONADENA, new genus 



Def/tiition. — ^Discocelidae with a semicircle of 7-11 prostatic ap- 

 paratuses around the male antrum ; otherwise as in Discocelis. 



CORONADENA MUTABILIS (Verrill. 1873), new combination 



FiGUEB 24, a, 6 



Polycelis mutahilis VEERnji, 1873, p. 746. 



Discocelis mutaUlis Verbiij., 1893, p. 493, pi. 40, fig. 7 ; pi. 42, figs. 6, Ga, 7. — Peaksb 



and Walkek, 1939, p. 16, fig. 1. 

 Discocelis grisea Peabse, 1938, p. 67, fig. 22.— Pearse and Littler, 1938, p. 235, 



pi. 20, fig. 1. 



Material. — Ten whole mounts in Pearse collection labeled Discocelis 

 ffrisea, including type ; set of serial sections made from one of these ; 



" Pearse spells the names of the suborders Acotylina and Cotyllna, in accordance with 

 the terminology proposed by him in his brochure: Zoological Names, a List of Phyla, 

 Classes, and Orders Prepared for Section F, American Association for the Advancement 

 of Science, 24 pp., Duke University Press, 1936. 



