460 SUMMARY OF CURRENT RESEARCHES RELATING TO 



structures, namely, witli two gelatinous, completely transparent and 

 structureless columns, the function of which is altogether unknown. 



New Form of Cestode, of the Type of the Cysticercus of 

 Arion.* — M. A. Villot found this new form, which he proposes to call 

 Cysticercus glomeridis, in a Glomeris ; it is a small spherical body, 

 about '001 m. in diameter, consisting of two very difl'erent parts. 

 There is a whitish transparent peripheral zone, and a brownish- 

 yellow opaque central portion. Tlie zone is a cyst, and the nucleus 

 represents the head, body, and caudal vesicle of a Cysticercus ; there 

 is a proboscis, which is invaginated into the head, four suckers, a 

 bulb, and a circlet of twenty hooks, which are arranged in two rows. 

 Between the body and the cyst there is a cavity filled with liquid ; 

 the investing membrane is not fibrillar, but is rather made up of fine 

 granulations, arranged in small groups and separated from one 

 another by a hyaline border. 



The cyst of the Cysticercus arionis has the same structure and the 

 same function, and in it also the body is invaginated into the caudal 

 vesicle. The differences between the two lie in the character of the 

 cephalic armature ; the discovery of the new form shows that the 

 Arion-type is not confined, as Krabbe thought, to the Mollusca. It is 

 I^ossible that the Tcenia is to be found in Scolopax rusticola. 



New Form of Segmental Organ in the Trematoda.t — M. E. 

 Mace finds this new type in a Distoraa taken from the intestine of 

 Vespertilio murinus ; it is ciliated and single, a rather large cup- 

 shaped organ being situated in the middle line, towards the posterior 

 third of the body ; in diameter it is almost half that of the ventral 

 sucker, and its orifice is invested by long vibratile cilia ; it gives off 

 four vessels, of which the two superior pass upwards and are soon 

 lost ; the two inferior take a transverse direction, and, after a short 

 course, open into the corresponding branch of the large terminal 

 cavity of this apparatus. The Disiomum in question has considerable 

 resemblance to D. ascidia, but differs from it in some details. 



Excretory Apparatus of the Turbellaria.t — M. Francotte com- 

 mences by referring to the discovery by Fraipont in the Trematoda 

 of the ciliated infuudibula of the excretory system of those animals, 

 and states that he has been led to investigate the Turbellaria. In 

 this preliminary communication he confines himself to Derosiomum sp. 



There are two principal longitudinal canals, which unite just 

 above the pharyngeal bulb, by a transverse branch, in the centre of 

 which is the external orifice of the water-vascular system. Posteriorly 

 the canals unite to form a glomerulus, and within each of them one 

 finds above thirty vibratile processes. Communicating with these 

 canals and anastomosing with one another so as to form a plexus 

 there is a system of much finer vessels ; but in the terminal infuu- 

 dibula of these the author has not been able to detect any ciliation. 

 The whole system of canals is filled with a clear liquid, the not 

 numerous corpuscles in which are identical with those found in the 



» Comptes Kendus, xcii. (1881) pp. 418-20. f Ibifl., pp. 420-1. 



:;: Bull. Acad. R. Belg., 1. (1881) pp. 30-4 (1 pi.). 



