ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 213 



in various stages of degeneration, and scar-like points were seen in the 

 intestinal coats. 



The author is of opinion that the migration path of these parasites 

 is outwards, that is, towards the lumen of the gut, but he does not 

 neglect to notice that the animals may burrow back into the mucosa 

 for a short distance. 



The connection between this parasite and the hsemoglobinuria, said 

 to be endemic in Eoumania, is very interesting. 



€. Crustacea. 



Monstrosity in a Crayfish.* — M. G. Stamati remarks that accessory 

 pieces have not yet been noticed except on the legs of Crustacea. He 

 describes a specimen in which the exopodite or squama of the left 

 antenna had a bifurcated appendage so placed that the free point of the 

 scale appeared to be trifurcate. This supernumerary growth appears to 

 arise from the left half of the scale, and there is no reason to suppose 

 that it is, as Eosel von Eosenhof would have suggested, the result of any 

 lesion, nor with Herklots, to regard it as a simple excrescence. It seems 

 to the author more reasonable to regard the appendage as a dependent 

 of the external half of the scale which is regularly developed ; it is only 

 because of the growth of its two halves that the two points have been 

 directed forwards. The investigation of the development of super- 

 numerary growths on the appendages of Crustacea can only be investigated 

 on young specimens and after ecdysis. 



NebaliidsB and Leptostraca.f — Prof. C. Claus publishes a mono- 

 graphic account of the Nebaliidse, on the structure of which he gave a 

 preliminary report more than ten years ago. The present memoir dis- 

 cusses the history, general morphology, general physiology, reproduction, 

 and distribution of the family. The systematic portion includes diagnoses 

 of Nehalia, Paranehalia, Nehaliopsis, and discusses the general relations 

 of the Leptostraca. 



The following forms have to be distinguished : — (a) Mature males, 

 characterized by the lank body, long furcal joints, bushy set^ on the 

 anterior antennte, and much elongated setje on second pair of antennae ; 

 (&) pregnant females with fans of bristles on the terminal joint of 

 each thoracic appendage ; (c) mature females and younger females of 

 variable size with a short equipment of bristles on the terminal joint 

 of the thoracic limbs ; {d) young males of variable size, characterized 

 by the short-ringed setose joints of the second antennse ; (e) larvee with 

 three-jointed antennary setse, and a still simple fourth pair of pleopods. 



The northern N. hipes O. Fabr. is a large variety of the Adriatic, 

 Mediterranean, and Atlantic N. geoffroyi. The form found on the east 

 coast of North America, those from Chili and Japan, and probably the 

 N. longicornis of New Zealand, are to be regarded as mere varieties of 

 the same species. 



The so-called rostral plate represents a third portion of the shell, 

 which forms a movable head-valve. It covers two rostral processes of 

 the head, and is so connected with them that raising the head elevates 

 the head-valve. The two last segments of the abdomen with the 



* Bull. Soc. Zool. France, xiii. (1888) pp. 199-201. 



t Arbeit. Zool. Inst. Wien (Claus), viii. (1888) pp. l-liS (11 pis.). 



