472 SUMMARY OF CURRENT RESEARCHES RELATING TO 



New Discodrilid.* — Maurice C. Hall describes Ceratodrilus thysano- 

 somus g. et sp. n. from crayfish collected near Salt Lake City. They 

 are not parasitic when young, the intestinal tract showing vegetable 

 detritus and small animals. In the adult stage the teeth are used to 

 break the skin of the host to suck the blood. Ingested muscle fibres 

 were found in the intestine. The prostomium was bilobed, but not 

 sharply, and each lobe was fringed with four or five papillae on lips. 

 The dental plates are brown, of a roughly crescentic outline, slightly 

 dissimilar, the ventral with six teeth, the dorsal witli seven, the teeth 

 being approximately uniform in size. The antero-dorsal border of the 

 head is furnished with a membranous border deeply incised to form 

 four tentacuhform appendages. The first seven trunk segments are 

 furnished with dorsal appendages extending from the lateral border in a 

 pointed band, the number of points usually six, on some segments seven 

 or eight. The unpaired spermatheca is cylindrical to flask-shaped, not 

 bifid. The penis is eversible. The testes are in segments V and TI. 



Notes on Scottish Leeches.f — John Ritchie, jun., contributes 

 notes on Protochpsis tesseUata, Glossosiphonia complanata, G. heteroclita, 

 HelohdeUa stagnalis, and Hsemopis sanguisuga. Of the last-named 

 sixteen specimens were found in August, under one stone in marshy 

 ground, each in a burrow of its own, and doubled up ventrally. At the 

 end of some of the burrows there was a cocoon. The animals were 

 very sluggish, and did not respond to light or touch for some minutes. 

 In the ecdysis the cuticle begins to peel off at the anterior sucker and is 

 turned inside out. 



Nematohelminthes. 



Oxyures of Mammals. | — L. G. Seurat has shown that the Oxyuridfe 

 of Mammals belong to two distinct series. The most highly developed 

 representatives of the first series are Dermatoxys and Oxyuris equi ; 

 those of the second series are represented by Passalurus Dujardin, and 

 by two new genera (Syphacia and Fusarella), which require to be estab- 

 lished for Oxyuris obvelata and 0. vermicularis respectively. The 

 diagnoses of these two new genera are given. 



Life-history of Spiroptera.§— L. G. Seurat describes the larvae of 

 various Nematodes of the Spiroptera group {Spirocerca sanguinolenta, 

 Physocephalus sexalatus, and Spirura gastropldla). He distinguishes 

 the larvffi of the first stage, which come out of the eggs in the abdominal 

 cavity of coprophagous beetles, from the hitherto overlooked free larvse 

 of the second stage. At the end of the second stage the larvse become 

 encapsuled, and thus protected pass into the definitive host. 



* Proc. U.S. Nat. Museum, xlviii. (1915) pp. 187-93 (3 figs.), 

 t Glasgow Naturalist, viii. (1916) pp. 8-11. 

 X C.B. Soc. Biol. Paris., Lxxix. (1916) pp. 64-8 (3 figs.). 

 § C.R. Soc. Biol. Paris, Ixxviii. (1915) pp. 561-5 (5 figs.). 



