242 SUMMAKY OF CUFiRENT EE3EAECHE3 RELATING TO 



made out. Sexnal reproduction is of course effected externally to the 

 Cecidomyife, and after it the males die down, while the females, if they 

 have the opportauity, make their way into the Cecidomyife larvae, where 

 they undergo a further change — they grow and the cells of their vagina 

 increase in size to such an extent that they project from the genital orifice. 

 As they continue to grow they press on the enteron, which they cause to 

 lose its primitive structure, and to take on the cord-like disposition already 

 described. 



Helminthocecidiae.* — Dr. F, Low commences with the description of 

 six new species of these gall-making Xematoids, trt'o of which should be of 

 especial interest to botanists, as they are the first galls which have been 

 described in mosses. The second portion of the memoir deals with advances 

 in our knowledge of species already described. 



7- Platylielininth.es. 



Helminthological Observations.! — Dr. 0. v. Linstow, in another com- 

 munication with this now familiar title, gives an account of his investiga- 

 tions into the life-history cf AiPjiostomum nigrovtnosum. The ova of the 

 hermaphrodite form foimd in the lungs of Bana fusca, contain the com- 

 pletely developed embryo ; these have the integument very thin, are • 1 3 

 mm. long and • 6 mm. broad ; on the eggs passing into the water they 

 escape and grow rapidly; on the fourth day mature males begin to be 

 observed, and on the eleventh, embryos were seen in the females, where a 

 pair are found in a cuticular tube, although, just as in Angiostomum 

 entomelas and A. macrostomum, there were primitively eight to ten eggs. 

 The history of development and the embryos themselves are exactly the 

 same in the three species. 



After some notes on Oxysoma hrevicaiidatum, Oxyuris ovocostata sp. n. 

 is described from the rectum of the larva of Cetonia aurata ; Distomum 

 talidum is a new species 17 mm. long, from the stomach of an unstated 

 species of dolphin; in connection with it a useful resume is given of our 

 knowledge of the dermomuscular tubes of the Trematoda ; in this new 

 species the subcuticula and the layer in which the circular and longitudinal 

 muscles run is of an elastic-fibrous nature ; this appears to be wanting in 

 Distoma with delicate bodies, and to be limited to large species with pro- 

 portionately stout cortical layers and well-developed muscles. 



The rare Distomum sj/icula:or, from the stomach of Jlits deaimanm, was 

 very correctly described by Dujardin, to whose account Dr. von Linstow 

 makes some additions. 



Cyslio.rcus tseniae uncinatae is a new cysticercus from the ccelom of 

 the coleopterous Siljjha laevigata, which agrees in its mode of development 

 with Urocystis prolifer ; but it is to be noted that the author objects to the 

 formation of new and various genera of Cysticercus, as all are but stages in 

 the development of Taenia. Dr. von Linstow repeats the essential parts of 

 his discovery of the intermediate host of Ascaris lumhricoides, to which we 

 have already diawn attention.! 



Distomum ingeiis.j — Prof. E. IVIoniez describes a new species of 

 Distomum, and has some remarks on the comparative anatomy and histology 

 of Trematodes. The new species is appropriately called ingens, as it is 

 6 cm. long, 2 cm. wide, and 1'5 cm. thick in its hinder region; the ova 



* Verhandl. Zool.-Bot. GeselL Wien, 1885, pp. 471-6. See Bot. Centralbl., xxviii. 

 (1886) pp. 107-8. 



t Arch f. Naturgesch., Hi. (1886) pp. 113-38 (4 pis.). 



i See this Journal. 1886, p. 989. 



5 Bull. Soc. Zool. France, xi. (1886) pp. 531-43 (1 pi.). 



