ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 521 



Prof. M. Stossicli * continues his helrainthological researches, de- 

 scribing seven new species of Distomum, of which six are figured. 

 Several other species of Distomum are discussed, and the occurrence of 

 some other parasites {Tsenia hotrioplilis, Ascaris ensicaudata, &c.) is 

 recorded. 



The Species of Distomum in Amphibians. f— Prof. M. Stossich 

 describes 16 species of Distomum parasitic in Amphibians, and seven 

 others somewhat doubtful. A list of 24 Amphibian hosts with their 

 known Distomum pai asites is furnished ; in Mana temporaria nine si)ecies 

 occur, in It. esculenta ten. 



Anatomy of Phylline Hendorfii.| — Dr. von Linstow gives an 

 account of the anatomy of this new species of ectoi)arasitic Treinatode, 

 which was found on the scales of Ccryphsena hippurus. The body is 

 ovate in form, 8*7 mm. long, and 5*2 mm. broad; at the anterior end 

 there are two suckers, and at the hinder end one which is very large. 

 The former are attached to the body in such a way that their hinder and 

 lateral margins are free; the latter, which is 3-1 mm. broad, carries 

 three pairs of hooks ; there are two stiff supporting lamellfe, which 

 obviously prevent the suckers from being torn off. All the three 

 sucking discs consist of a cuticle, which is much stronger on the dorsal 

 than on the ventral surface, and of a well-developed dorsoventral 

 muscular mass, in which separate cells are imbedded ; the parenchyma 

 is feebly develoj)ed, is fibrous, and contains no nuclei. The three pairs 

 of hooks Viiry a good deal in structure; the most anterior pair is sur- 

 rounded by two tendons which lie in a sheath where they can work 

 backwards and forwards. While the hooks of most Trematodes and 

 Cestodes are organs which serve for attachment, those (f this form are 

 clearly organs which are adapted to loose the jjarasite from its place of 

 attachment ; the median long hooks have the function of surrounding 

 the free margin of a fish's scale. These hooks are of a horny nature 



The cuticle consists of a plexiform fundamental tit^bue, the spaces in 

 which are filled by rods of various sizes, better developed on the dorsal 

 than on the ventral surface, and giving a villous aj^pearance. In the 

 dorsal cuticle there are also numerous rounded glands, which probably 

 secrete mucus. The muscles of the cortical layer must be distinguished 

 from those of the parenchyma ; they are either longitudinal, circular, or 

 diagonal in direction. The muscles of the parenchyma are uncommonly 

 strong, and are remarkable for passing through the testes, ovary, and 

 shell-gland. 



The mouth is a large, almost sjiherical organ, • 78 mm. in diameter ; 

 while it is well developed, the intestine is very feeble, and we must 

 suppose, therefore, that the ingestion of food requires much greater 

 strength than its propulsion and absorption. A rich vascular system 

 traverses the whole body ; it is formed of two large longitudinal trunks 

 which divide the body into three nearly equal thirds ; posteriorly they 

 unite to form a cylindrical pulsatory vesicle which is covered by the 

 posterior sucking disc, and opens by a foramen caudale. Anteriorly" they 

 widen out into large vesicles which vary considerably in their condition 

 of contraction ; one is almost always much larger than the other, and both 



* Boll. Soc. Adriat. Sci. Nat., xi. (1889) pp. 23-30 (2 pis.). 



t T. c, pp. 60-74. 



; Arcliiv f, Mikr. Auat., xxsiii. (1889) pp. 1G3-80 (2 pis.). 



