ZOOLOGY AND BOTANY, MICKOSCOPY, ETC. 473 



Host of Rictularia proni.* — L. G. Seurat described this Nematode 

 from the stomach of a mongoose (Herpestes ichneumon), but he has not 

 re-discovered it there, whereas he finds it abundant in a rat {Arvicanthis 

 harharus). It is nearly related to some other species from Rodents, 

 especially to R. cristata. It is one of a series marked by the shortness 

 of the ovijector, the minuteness of the male, the absence of caudal alee, 

 the presence of sessile genital papillae, and the inequality of the spicules. 

 In R. proni there is an extraordinary difference in size between the 

 male (not over 4. "5 mm.), and the female (39 "7 mm.). 



Host of Protospirura numidica.f — L. G. Seurat found this Nema- 

 tode in the stomach of Felis ocreata in Algeria, and compared it with 

 another si:)ecies'^roiospirHra muris) from the rat {Mus decumanus). But 

 the subsequent discovery of P. numidica in a rat (^Arvicanthis harharus) 

 seems to show that its occurrence in the cat was accidental. A careful 

 comparison of the two species is made, and it is held that P. muris 

 shows itself more evolved than P. numidica, the points referred to being 

 the greater length of the tail ia the male, the presence of small peduncu- 

 late pre-anal papillae, the more anterior position of the vulva, the short 

 and pyriform vestibule like that in other Spiruridse {Hartertia and 

 Hahronema). 



Platyhelminthes. 



Secondary Echinococcus Infection of the Pericardium.J^ — F. Deve 

 finds that this is exceptionally due to a bursting of a cyst in the liver or 

 lungs, but that it is almost invariably due to a primary cyst in the heart 

 itself. The primary cyst may l)reak first outwards into the pericardial 

 serous sac ; it often bursts subsequently into the interior of the heart. 



North American Frog Lung-flukes. § — W. W. Cort has made a 

 revision of the Trematodes of the genus Pneumojioscus from the lungs 

 of species of Ra7ia and Bufo. A given host may harbour even in a 

 restricted locality several species, and one species may infest several 

 different hosts. Two different species may occur in the same frog, or 

 even in the same lung. The heaviest infection was in a specimen of 

 ■Rana pipiens, which had twenty full-grown specimens of Pneumonoacus 

 m.ediopIexus in one lung and twenty-two in the other. The parasites 

 almost filled the lung cavity, their actual bulk being greater than that 

 of the lung tissue. Species differ greatly in their cuticular spines and 

 reproductive system. Practically nothing is known of the life-history, 

 save that stages of P. variegatus have been found in the damsel-fly, 

 Calopteryx virgo. The author gives a careful account of six species and 

 a diagnostic key. 



* C.R. Soc. Biol. Paris, Ixxix. (1916) pp. 14G-9 (2 figs.), 

 t C.R. Soc. Biol. Paris, Ixxix. (191G) pp. 143-6 (5 figs.). 

 : C.R. Soc. Biol. Paris, Ixxviii. (1915) pp. 734-6. 

 § Trans. Amer. Micr. Soc, xxxiv. (1915) pp. 208-40 (3 figs.). 



