1922.] 



H. A. Baylis and R. Datjbney : Parasitic Nematodes. 



313 



diameter. The distance from the head end to the posterior end of the oesophageal 

 bulb is 2 3-2 -5 mm. The bulb measures 0-45-0-6 mm. in length and 0'4-0'48 mm. in 

 diameter. The cervical papillae are at 1-5-1-6 mm., the nerve-ring at o'52-o*58 mm., 

 and the excretory pore at 1-7-1*95 mm., from the anterior end. 



The tail of the male (fig. 49) is 0/45-0-55 mm. long. The sucker, which is deep 

 and strongly muscular, is situated at about im mm. in front of the cloaca. There 

 are nine pairs of caudal papillae and the usual median precloacal papilla. The 

 arrangement is the same as in Z. annandalei, except that one of the three pairs im- 

 mediately in front of the cloaca is absent. The two pairs present in this position 

 are small, and the three more anterior pairs much larger. The spicules are relatively 

 large, measuring 2*9 mm. in length and om mm. in width. The accessory piece is 

 similar to that of Z. annandalei. 



Fig. 49. — Zanclophorus kempi. Posterior end of male ; lateral view. 

 a. p., accessory piece; s., sucker. 



The tail of the female is bluntly conical, and measures o\55-o - 8 mm. in length. 

 There is a pair of caudal papillae at 0*27 mm. from the tip. The vulva is situated 

 at 4*o-4'8 mm. from the posterior end. The vagina is simple and narrow, about 

 2 mm. long, and runs forward as usual from the vulva. The eggs are oblong-oval in 

 shape and measure 0-125-0-137 mm. X 0-075-0*085 mm. The content is unsegmented. 



It is always interesting to discover fresh cases of close relationship betwen the 

 parasites of closely-related hosts, as showing how parallel evolution may be taking 

 place in both hosts and parasites simultaneously. The present case is a very good 

 example, neither the hosts nor their parasites having as yet developed sufficiently 

 divergent characters to obscure their extremely close relationships. 



Dr. Annandale has been good enough to supply us with the following interesting 

 note on the hosts of our new genus : — 



