740 DR. T. S. COBBOLD ON NEW OR RARE ENTOZOA. [Nov. 18, 



me that Dr. Little, of Shanghai, is diligently engaged in working 

 out the structure and development of the parasite. 



Dr. Krabbe, of Copenhagen, has likewise supplied some interest- 

 ing particulars ; but, in the absence of any references, I am led to 

 conclude that the Danish author's observations are based on the 

 previously published statements of Prof. Leidy (" Husdyrenes 

 Indvoldsorme," Tidsskrift for Vet. 2den Rsekke, ii. 1872). 



On the the 15th of April last I examined a number of these 

 worms, two of which, male and female, are represented in the ac- 

 companying Plate. To the naked eye the sexual differences are 

 readily discernible. The female (fig. 5) maintains almost through- 

 out a uniform calibre of about ■£% inch ; but at the head it diminishes 

 to t^j inch, and at the tail to about y^y inch, the caudal point being 

 bluntly convex. The oviducts of all the females examined were 

 crowded with eggs, and in certain situations the eggs were collected 

 together in the form of large ovoid masses. The largest eggs had a 

 long diameter of -%!-$ inch, with an average breadth of -j- 4 x inch. 

 These contained coiled embryos ; the diameter of their bodies vary- 

 ing from 4( / 01) inch to ^g inch. 



The male parasite is readily recognized by its comparatively slender 

 body, having a diameter of about ^ inch, and also by its elegant 

 spirally curved tail, which is three or four times twisted upon itself 

 with the regularity of a corkscrew (fig. 6). The coiled portion is 

 much narrower than the body of the worm, and it finally dwindles 

 down to a breadth of -gfo inch, its extreme point being blunt, as in 

 the female. Within a short distance of the extremity the two spicules, 

 of unequal length, may often be seen projecting from the cloacal 

 outlet, this part of the worm being also furnished with a well- 

 marked horseshoe-shaped bursa (fig. 7). This organ may be de- 

 scribed as consisting of two transparent folds or extensions of the 

 cuticle, each lateral division of the hood being supported by four 

 oval glandular rays. The rays are apparently eight in number, and 

 arranged in pairs. The uppermost pair is the largest, the other 

 pairs gradually decreasing in size from above downwards. When 

 viewed laterally, these oval rays present a beaded appearance, col- 

 lectively forming a rather striking microscopic object. The dia- 

 meter of the largest ray is only about the yoVo hich, whilst that of 

 the smallest is not more than y^yu inch from side to side*. 



As seen in the drawing, the epidermal layer of the skin was 

 generally found projecting more or less beyond the limit of the 

 dermis. I regarded this as a post mortem production. In one case 



* Since this paper was read to the Society my attention has been called to a 

 much more detailed description of the worm by Mr. Welch, of Netley, commu,- 

 nicated to the 'Monthly Microscopical Journal' for October 1873, p. 157. The 

 author gives many particulars that have escaped my notice, and he also inter- 

 prets some of the facts observed by us both in a very different sense from that I 

 have adopted. He recognizes but one spicufvm, and regards the oval rays as 

 generative appendages, of the nature of vesicida seminales, communicating with 

 the seminal duct. He observed twelve of these oval appendages, and, amongst 

 other things, describes the intestinal tube as terminating in a blind caecal extre- 

 mitv.— T. S. C. 



