300 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Crassicauda crassicauda.* — H. A. Baylis reports the occurrence of 

 this Nematode in Cuvier's whale {Ziphius cavirostris). A (fragmentary) 

 specimen was found near the kidneys, liavin<^ evidently been pulled out 

 of the renal tubules. It seems to have been previously found in four 

 other whales. The mouth is a narrow slit-like aperture, whose long 

 axis runs dorso-ventrally. It is lined with very thick cuticle. On 

 either side of the mouth there is a small rounded papilla. Laterally 

 to this there are, towards each side of the head, three more papillae, 

 mastoid in shape, and but slightly raised. The general appearance of 

 the mouth and papilla3 is very Filaria-like. 



Platyhelminthes. 



Tapeworm of Ostrich.f — F. E. Beddard describes a species of 

 Davainea from Sir uthio /iiasaicus, vthich is certainly not to be confounded 

 with von Linstow's Davainea struthionis, but may be the same as the 

 worm described by Parona as Tseiiia struthionis. The scolex, I'l mm. 

 in diameter, has a double row of 130 hooks in all; the suckers arc 

 unarmed ; the scolex and anterior part of the body abound with 

 calcareous corpuscles, which also occur posteriorly. There is no neck. 

 The segments of the body are not longer than broad ; the ripe segments 

 are not moniliform ; the genital pores are unilateral ; the cirrus-sac 

 reaches to the nerve-cord ; the dorsal excretory vessel is absent from 

 the posterior region of the body. The ova are imbedded singly in 

 parenchyma extending into the cortex. 



Trematode Genus Stephanochasmus.:]: — Henry S. Pratt gives a 

 description of Stepluuiochasnms casus Linton from the rectum of two 

 common fishes in the Gulf of Mexico— the gray snapper {Lutianus 

 griseus) and the yellow tail {Ocyurus chrysurus). The living worm is 

 deep red because of the blood in the capacious intestine ; it bears large 

 spines characteristic of the genus. The internal structure exhibits 

 several novel and interesting features. 



Structure of Didymorchis.§ — W. A. Haswell describes D. cherapsis 

 sp. n., a very small Rhabdoccele, not exceeding a millimetre in length, 

 which lives in the branchial cavity of a common crayfish of Eastern 

 Australia, Cheraps hicarinatus. Another species, D. astacopsidis sp. n., 

 occurring in Astacopsis serratus, is briefly dealt with. The genus 

 Didymorchis was established by Haswell in 1900 for a Rhabdoccele from 

 the New Zealand crayfish Paranephrops neozelanicus ; it differs from 

 other genera in the family Dalyellidae (formerly Derostomidse) in the 

 character of the excretory system and in the restriction of the cilia to 

 the ventral surface. 



These minute colourless Ehabdocoeles only occur in association with 

 crayfishes, and show certain adaptations to their special mode of life. 



* Ann. Mag. Nat. Hist., xvii. (1916) pp. 144-8 (1 fig). 



t Proc. Zool. Soc. London, 1915, pp. 589-601 (6 figs.). 



X Parasitology, viii. (1916) pp. 229-38 (1 pi.). 



§ Quart. Joum. Micr. Sci. Ixi. (1915) pp. 161-9 (1 pi. and 1 fig.). 



