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A NEW SPECIES OF PLANOCERA (P. GILCHRISTI) 

 FROM SOUTH AFRICA. 



(PL XV., tigs. 1-7). 



By Lydia Jacubowa, Archangel. 



Among the material at my disposal occurred the above Polyclad 

 which had been found by Dr. Gilchrist near the Marine Laboratory 

 at Cape Town. A single specimen only was available. Although 

 considerably contracted, it was on the whole very well preserved 

 both with regard to external features and histological structure. 



The length of the animal is 40 mm., the breadth 28 mm., and the 

 thickness varies from 1 mm. at the sides to 1J— 2 mm. in the central 

 region. The form of the body is broadly oval, both ends being 

 similarly rounded ; the margin of the body is strongly folded. It is 

 of a fairly firm consistency and very little transparent. 



The ground colour of the back of the specimen (preserved in 

 alcohol) is yellowish w T hite. On this are to be seen black spots 

 of irregular shape, and these are grouped together in small heaps 

 equally distributed over the surface of the back. They form a con- 

 tinuous black line only in the dorsal middle line, in the region of the 

 reproductive organs. On the other hand, the region of the brain 

 area is almost devoid of spots and forms a clear unpigmented area. 

 The small spots are also found on the tentacles in very diminished 

 numbers. They are formed of the pigment which lies in the dorsal 

 epithelium of the body in the form of black particles. 



On the dorsal side of the animal two high pointed neck-tentacles 

 can be distinguished, situated 9 mm. from the anterior end, that is, 

 at the end of the first fourth of the body. The distance between them 

 is 2 mm. It is seen by microscopical examination that each tentacle 

 has, at its base, from about fifteen to twenty large, well-developed 

 eyes (fig. 2). The eyes of the brain area, which are not much 

 smaller, are arranged in two rather elongate groups, which lie on 

 the lateral margin of the brain, over which they extend in front and 



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