ZOOLOGY AND BOTANY, MICROSCOPY^ ETC. 843 



Spadella marioni.* — P. Gourret has a note on this new Cliaeto- 

 gnath, wliicli is found in abundance in the Gulf of Marseilles, and is 

 characterized by the quadrangular form of the terminal fin, and by 

 the reduction of the lateral fins, which are always without rays. The 

 new form is also characterized by the presence of a paired, flattened 

 and quadrangular ganglionic mass, placed at the postero-lateral angle 

 of the "brain." The peripheral nervous plexus is placed between 

 the epidermis and the subjacent musculatui-e. Notwithstanding the 

 doctrine of Grassi, the author thinks that some of the nerve-fibres end 

 in muscular fibres. The tactile prominences have no rods, and their 

 hairs are in direct relation with the tactile cells ; from the base of 

 these latter there is a prolongation which is nervous in character, and, 

 as a very fine process, passes between the muscular fibres and forms a 

 fusiform swelling, which, at its inferior pole, is again continued on 

 to a nerve-trunk. JSTo ciliated circlet, vestibular or post-cerebral 

 follicles were observed in S. marioni. Contrary to Grassi, Gourret finds 

 that the glandular cells of the intestine are ordinarily smaller than 

 the absorbing cells ; and he looks upon the cilia as having only a 

 relation to the passage of food, a process which may be aided, at 

 certain points, by the external layer of the intestine, the fibres of 

 which have some muscular characters. 



New Nematoid.l — F. E. Beddard describes a new Nematoid 

 which he found in the perivisceral cavity of Pleurochceta moseleyi (supra, 

 p. 839), and which is of interest as apj)roaching, in some characters, 

 the free-living forms. The author points out that, where Nematoids 

 are found as parasites, but have structural affinities to free-living 

 forms, the phenomenon may be explained as being due (1) to their 

 accidental presence in the body of their host, e. g. Dorylamius stag- 

 nalis, which was found by Dujardin in the intestine of the carp ; 

 (2j to a free-living form passing into a parasitic stage, e.g. Ascaris 

 nigrovenosa, or the Dionyx lacazii of Perrier ; or (3) to similarity in 

 conditions of life, e.g. this new form, Bicelis jjleurochcetoe, which lies 

 in a perivisceral cavity freely open to the exterior by a series of large 

 dorsal pores, as well as by the apertures of the generative organs. 



In the species described there is only a single mouth-papilla, an 

 arrangement hitherto unobserved, and possibly explicable as being due 

 to the retention of a boring-papilla, such as is found in the young of 

 Ascaris and Cucullanus. 



Male of Oxyuris curvnla.| — A. Eailliet points out that one of 

 the peculiarities in the life-history of Oxyurids consists in the ex- 

 treme rarity of the males ; not only are they always smaller and much 

 more difficult to find, but their number seems also to be less consider- 

 able than that of the females. At any rate, the male of the Oxyurid 

 found in the horse has, as yet, been but very slightly studied. In it 

 the testicle has the form of a blind tube, which is somewhat coiled, 

 and so sometimes surrounds the intestine; its first half, or testicle 



* Comptes Eendus, xcvii. (1883) pp. 861-4:. 



t Proc. E. Physical Soc. Edin., vii. (1883) pp. 229-34 (1 pi.). 



X BuU. Soc. Zool. France, viii. (1883) pp. 211-16 (1 pi.). 



3 L 2 



