DIAGNOSIS OF ALL KNOWN SPECIES OF PLATVCTENEA. 93 



conib-plates absent in adult; tentacles without branches; pharyngeal 

 cavit>' with an accessory opening on each transverse end of body upon 

 the summit of a chimney-like vertical elevation; meridional canals reduced 

 into short diverticula . from perradial canals; branching canals present, 

 but rather sparse, showing no anastomoses; gonads arising on lateral 

 walls of the above diverticula; viviparous, eggs developing into cydippid- 

 like embryos in brood-cavities at the lateral parts of body. One species: 

 Tjalfilla tristoma Mortensen ('10). 

 Size : 20 x 5 mm. (in large specimens). Locality : West coast of 

 Greenland, found attached to Uinbelhda. 



Family Coeloplanidae Willey ('96). 

 Genus Coeloplana Kowalevskv ('80). 

 Creeping; body flat, shape extremely changable; brightly coloured; 

 comb-plates absent in adult; tentacles with numerous branches; meridional 

 canals well developed, branching canals showing rich anastomoses; sperms 

 developing in some compact separate masses, eggs in a continous linear 

 tract, from each canal representing meridional canal; sperm-mass with 

 a duct opening to dorsal surface of body; larva cydippid-like. 5 species : 

 Coeloplana metschnikowii Kowalevskv ('80). 

 Colour greyish; without " dorsal tentacles " (?). 

 Size : 6 X 4 mm. Locality : Red Sea near Tor. 



C. zvilleyi Abbott ('01). 

 Colour variable, may be purplish, reddish or rosy, scattered with 

 yellowish-white spots on the margin of body and at the bases of dorsal 

 tentacles. Size : 20-60 mm. (in extended state). Locality : Misaki. 

 C. ndtsitkurii Abbott ('01). 

 Colour less variable than the former or the next species, generally 

 light yellowish-brown, without yellowish-white spots. Size : nearly the 

 same as above. Locality : Misaki. 

 C. bocki KoMAi ('20). 

 Colour variable as much as in C. luilleyi, or even more, always 

 forming a dozen or more streaks parallel to tentacular axis, yellowish- 

 brown spots absent. Locality : Misaki, found attached to Dendi'onephthya 

 sp. Size: ca. 15 mm. (in extended state). 

 C. gonoctena Krempf ('20). 

 Colour milky-white, scattered with brown spots. Size : 10-30 mm. 

 in length, 5-10 mm. in breadth. Locality: Coast of Annam, found 

 attached to Alcyoiduvi krempfi Hickson. 



