ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 249 



Schneider compares this Sphserularia, which he proposes to re- 

 name cunctatrix, with the Simondsia paradoxa described by Cobbold, 

 in which a similar protrusion of the uterus occurs. He corrects a 

 former description of the tail of the male form, and adds a note in 

 reference to a recent communication by Leuckart.* 



New Nematodes and Trematodes.f — Dr. O. v. Linstow com- 

 municates a series of notes, chiefly of systematic importance, on 

 various Nematodes and Trematodes. He defines the following new 

 species : — (a) Ankylostomum perniciosum from the tiger, Ascaris Thij- 

 malli, A. Lotas, Filaria conoura in Anguilla, F. Glomeridis, F. Ves- 

 peruginis, Agamonematodum Bombinatoris, Oxyuris Glomeridis, Triclio- 

 soma filiforme in Triton, Distomum Anguis, and D. Limnsese ovatse. 

 Most of the specific names indicate, as usual, the habitat. Descrip- 

 tions of the specific characteristics of more than a dozen previously 

 observed forms are given. The skin-casting of the larval Dorylaimiis 

 stagnalis is briefly noted, and it is, from analogy, maintained that 

 Perroncito's description of a larval encapsuling, and not skin-casting, 

 in Anguillula stercoralis and Ankylostomum duodenale is a misinter- 

 pretation. 



Von Linstow outlines the embryology of Eolostomum cornucopiae. 

 (a) The germinal cell or true ovum is inclosed in a yolk-mass, which 

 is either merely granular or composed of small nucleated or non- 

 nucleated cellular elements, (b) A morula-mass of a few nucleated 

 cells is soon formed, inclosed by the now wholly cellular yolk, 

 (c) The next stage is that of the blastula-formation, the cells of 

 which exhibit a peculiar very lively molecular movement of the 

 granules, (d) An epiblast and hypoblast appear, the latter sur- 

 rounded by the yolk-cells, (e) The germinal layers increase at the 

 expense of the yolk-cells. Within the granular cells of the yolk- 

 mass granular nuclei are formed, which become free, acquire almost 

 the dimensions of a cell, form a central nucleus and nucleolus, which 

 eventually take up an excentric position, and so result in bodies not 

 unlike the sperm-cells of many Nematodes. The boundary between 

 the epiblast and the unused yolk remainder becomes indistinct. 

 {/) From the epiblast granular ciliated cells are formed ; the cells 

 of the embryo and the two dark eye-spots can be seen within. 

 {g) About a month after the first observation the embryo is seen 

 moving, lying somewhat bent within the egg ; the crescentic eye- 

 spots, the four movable ciliated tufts, and the motion of the cuticular 

 cilia are soon recognizable. The yolk remnant is reduced by the 

 motion of the embryo to a granular mass, and the Tetracotyle-like 

 organism is soon liberated. Its further history was described in a 

 previous research. 



Post-embryonal Development of Trematoda.t— HerrW. Schwarze 

 first deals with Cercaria armata from Lymnseus stagnalis ; he has been 

 able to detect the ending of the finest vessels in ciliated infundibula ; 



* See this Journal, v. (1885) p. 810. 



t Arch. f. Naturgesch., li. (1885) pp. 235-55 (3 pis.). 



X Zeitschr. f. Wisa. Zuol., xliii. (1885) pp. 41-86 (1 pi.). 



