136 Dr. R. Bergh on Phidiana lynceus. 



possess urticating cells. Besides it is easy to show that in 

 several ^olididae (for instance, species of Glaucusj which live 

 almost exclusively on one kind of food, Vellella and Porpita) 

 the urticating threads found in the digestive tube and derived 

 from the food are quite diiferent from those found in the urti- 

 cating cells and secreted by the animals themselves. Nor does 

 that theory agree with the fact that the urticating cells are to a 

 great extent not free in the sacs, but enclosed in cysts, and 

 become free only by the bursting of the latter. Dr. Bergh refers 

 finally to the great analogy in anatomical respects between 

 ^olididae and Pleurophyllididge, and concludes that the urti- 

 cating cells in the sacs are the product of the ^olididse them- 

 selves, and not derived from their food. 



On the back of one of the specimens of Phidiana lynceus^ 

 immediately behind the second group of papillae, a deep de- 

 pression was observed, as if some body had been located there 

 but had fallen off ; in the middle of this depression an irregular 

 round opening of 0*25 millim. diameter was seen. The sexual 

 gland was very much atrophied, only the foremost and hind- 

 most lobes being well developed. In the second specimen a 

 round opening, 0*75 millim. broad, was observed in exactly 

 the same place as in the first specimen, and a pointed promi- 

 nence was seen in the opening ; another, much smaller opening 

 was seen in front of the one described. On the sides of the 

 animal several yellowish slanting bodies seemed to shine 

 through the integuments from inside. When the inner cavity 

 was examined the greater part of the space usually filled by 

 the sexual gland was occupied by a parasite, the gland being 

 atrophied as in the first individual. The parasite was a Co- 

 pepodous crustacean, with the back downwards, the head 

 forwards, and the posterior extremity reaching out into the 

 larger opening before described. This crustacean reminded 

 one of the Splanchnotrophus hrevipes of Hancock and Norman, 

 but differs from this in several important points, viz. the 

 well-developed large cephalothorax, the articulated abdomen, 

 the absence of true limbs, the peculiar arm-like lateral 

 prolongations of the body, the dorsal prolongation, and the 

 remarkable prolongation of the abdomen (which forms a kind 

 of tail) . 



The only specimen was a female : no males could be dis- 

 covered ; and Dr. Bergh recalls with good reason Professor 

 Kroyer's remark, in his last contribution to the history of pa- 

 rasitic Entomostraca (Natm'historisk Tidsskrift, ser. 3. ii. 

 1863, p. 396), that ^' whenever the incompleteness of our know- 

 ledge compels us to found genera on females only, or to group 

 species of which only the female is known together with others 



