ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 519 



known. The hosts comprise over a hundred reptiles, birds, and 

 mammals. 



Female Genital Ducts of Acanthocephala.* — Herr P. Kniipffer 

 corroborates the observations of Saefftigen on this subject. Indepen- 

 dently of the latter, he demonstrated that the oviduct, described by 

 Leuckart as single, is really double. The muscular structure or 

 " Glocke " which receives the embryos from the body-cavity, the double 

 ducts which are continuous with the former, the so-called "uterus" in 

 which the ducts merge, the musculur and glandular terminal portion or 

 " vagina," are described and figured. KuiipiFer's researches included 

 Echinorhyncus hseruca Rud., E. pohjmorphiis Breinser, E. glohulosus Rud., 

 E. strumosus Eud., E. pseudosegmentatiis n. sp., which are all separately 

 discussed. The author contributes some notes on the body-wall and the 

 musculature, and denies the legitimacy of the genus Paradoxites, which 

 Lindemann sought to establish as distinct. 



y. Platyhelminthes. 



Gunda ulvae.f— Herr A. Wendt is of opinion that the Planaria 

 iilvse of Oersted should be placed in the genus Gunda ; the chief cause 

 for this change lies in the close resemblance exhibited by the terminal 

 organs of its generative apparatus to that of G. segmentatn ; the course 

 taken by the oviducts, their union, and the opening of the unj^aired 

 oviduct into the uterine duct. In most fresh-water Planarians the uterus 

 lies between the pharyngeal pouch and the penis, but in Gunda the penis 

 is near the pharynx and the uterus is placed further back. Close 

 similarity is also to be detected in the arrangement of the central 

 nervous system. 



On the other hand, the gonads do not in G. ulvse exhibit the same 

 marked segmental arrangement as in G. segmentata ; before, however, 

 judgment is passed on this point a larger number of marine Planarians 

 must be examined. 



Nervous System of Nemertines.^ — Herr O. Biirger has a pre- 

 liminary communication on the nervoias system of Nemertines. On the 

 whole he confirms the observations of Hubrecht. He has succeeded in 

 discovering an anal commissure of the lateral nerves in Cerehrafidus. 

 The oesophageal nerve-trunks (vagus of Hubrecht) of that worm, of 

 Langia, and of Polia are connected by a strong commissiire, which con- 

 tains ganglionic cells. The proboscis of Schizo- and Palseo-nemertinea 

 is innervated by two ascending nerves given off from the ventral 

 ganglion, which form a layer around a muscular zone. In the Hoplo- 

 nemertinea ten to seventeen cords enter the proboscis, where their coui-se 

 is constant ; they are connected by transverse fibrous bands, which sepa- 

 rate the longitudinal musculature into two concentric layers. In the 

 body there is an inner layer between the circular and internal longi- 

 tudinal musculature, in addition to the peripheral nervous layer. Besides 

 the already known sensory organs, the author fouml an altogether ter- 

 minal epithelial invagination on the head, to which a nerve passes. The 

 lateral cephalic pits of the Hoplonemertinea are provided with sensory 

 cells which carry rods. 



* Mem. Acad. Imp. Sci. St. Petersb., xxxvi. (1888) pp. 18 (2 pis.), 

 t Arch. f. Naturgesch., liv. (1889) pp. 2.^2-74 (2 pis.), 

 j Nachr. K. Gesell. Wisa. Gottingeu, 1888, pp. 479-82. 



