174 SUMMARY OF CURRENT RESEARCHES RELATING TO 



the nervous system, the gut, and the gonads in fresh-water Mermithidae. 

 In systematic distinctions importance must be attached to the fine 

 structure of the integument, the number of longitudinal bands (eight 

 or six), the spicules, and the structure of the vagina. He deals with 

 species of Mermls, Neomermis, Mesomermis, Limnomerrnis, Pseudo- 

 mermis, Bathymermis, Paramermis, and Eumermis. 



Reproductive Ducts of Cestodes.* — Robert Schaefer has studied 

 these, with especial reference to the conditions of the epithelium. He 

 traces their development. For Bothridium pythonis he finds, as Schmidt 

 did for Bothriocephalus lotus, that the testes and yolk-glands arise, in 

 the parenchyma of the medullary and cortical layers, quite apart from 

 the primordia of the other reproductive organs. In Tsetiia the testes 

 only have this independent origin. In the young stages of both there 

 is an epithelium lining the genital ducts. In parts which communicate 

 with the surface the epithelium degenerates and a cuticle is differentiated 

 from without inwards, a process associated with an insinking of epithelial 

 nuclei. The cuticle of Cestodes is ectodermic, not mesodermic. 



New British Trematodes. — W. Nicoll t describes AncylocfMium 

 typicum g. et sp. n., a small Trematode from the horse-mackerel (Trach- 

 urus trachurus), and Zoonogenus vividus g. et sp. n. from the sea-bream 

 (Sparus centrodontus) . The first of these stands very much by itself, 

 as is shown by the accessory genital sac, the unique configuration of the 

 intestinal diverticula, and the peculiar condition of the yolk-glands. 

 The second resembles Zoogonoides, but has an unarmed cirrus, a very 

 highly-developed vagina, and much smaller egg-capsules. 



In another paper $ the author describes Hemipera ovocaudata g. et 

 sp. n. from Lepadogastcr gouanii, Derogenoides o meatus g. et sp. n. from 

 Trachinus draco, Lepidauchen stenostoma g. et sp. n. from Labrus berg- 

 gylta, and PodocotyU syngnathi sp. n. from pipe-fishes. 



Reproduction in Fresh-water Triclads.§ — Adolf Burr has studied 

 species of Planaria, Dendrocozlum, and other forms. Fertilization is 

 mutual. There is no receptaculum seminis in the strict sense. The 

 spermatozoa accumulate in a part of the oviduct — the tuba. The 

 so-called " uterus " is rather a bursa copulatrix. The egg-capsule is 

 formed in the atrium, not in the so-called uterus. The erythrophilous 

 shell-glands form the secretion that becomes the matrix of the shell. 

 The rest of the shell of the egg-capsules is formed from spherules 

 contributed by the yolk-cells. It appears that the muscular glandular 

 organ is of the nature of a weapon. 



Peculiar Association of Two Species of Convoluta.|| — Marcel A. 

 Herubel reports from Roscoff the occurrence of the widely-distributed 



* Zool. Jahrb., xxxv. (1913) pp. 583-624 (6 pis. and 2 figs.). 



t Parasitology, v. (1913) pp. 197-202 (1 pi.). 



X Parasitology, v. (1913) pp. 238-46 (1 pi.). 



§ Zool. Jahrb., xxxiii. (1912) pp. 595-636 (1 pi. and 11 figs.). 



j|| Bull. Soc. Zool., xxxviii. (1914) pp. 319-20. 





