1910.] ENTOZOA OF THE HIPPOPOTAMUS. 235 



be calcified filaria worms. A prolonged search resulted in the 

 discovery of four living specimens, but unfortunately they were 

 all females, and the description of the species must necessarily 

 remain incomplete for the present. 



The parasites measure 100 mm. in length and have a transverse 

 diameter of 0"4 mm. The skin is quite smooth, the mouth is 

 simple, and does not appear to be provided with definite papilla?. 

 The oesophagus, like that of other filaria in mammals, is long and 

 slender, measuring 2*6 mm. by - 12 mm. At 0*5 mm. from the 

 mouth it is crossed by the nerve-ring. The anus is situated 

 - 45 mm. from the tip of the tail. The vulva opens 1"55 mm. 

 from the anterior end. The vagina is a muscular- walled tube 

 passing directly backwards therefrom to divide at the level of the 

 junction of the oesophagus with the chyle intestine into two long 

 uterine tubes. These tubes are at first narrow (0'05 mm.) and pass 

 backwards for a considerable distance side by side ; they become 

 distended later with embryos, and together with the ovarian 

 tnbules occupy the perivisceral cavity from 0*8 mm. behind the 

 vulva to the anus. 



The posterior end of the worm is bluntly rounded, and in the 

 middle line teimiinates in a small cuticular knob with a slightly 

 depressed tip. On either side of this cuticular termination the 

 integument is distinctly raised by a pair of large fleshy papilke. 



This species is apparently closely related to Filaria demarquai 

 of man. 



3. Cobboldia vivipaba, gen. et sp. n. (Text-fig. 27 B, C.) 



The mucous secretion upon the lining of the stomach of the 

 Hippopotamus was infested with myriads of a minute form of 

 Nematode that is, when alive, almost invisible to the naked eye on 

 account of its transparency. The males and females resemble 

 each other very closely, and can only be distinguished by a micro- 

 scopical examination. The former measure 4 - mm., the females 

 4 - 3 mm. in length. The skin has no transverse stria?, but longi- 

 tudinal lines are visible through the cuticle. In the male the 

 body maintains an almost uniform diameter of - 09 mm. from the 

 excretory pore to the genital opening. The body tapers anteriorly 

 from the excretory pore to 0*03 mm. at the head, and likewise 

 posteriorly from the anus to end at the tail in an acicular point. 

 In the female a uniform diameter of 0*1 mm. is only maintained 

 in the second quarter of the body length, whence it tapers gradually 

 to 0*04 mm. at the head, and uniformly through the whole of the 

 posterior half of the body to a sharp-pointed tail similar to that 

 in the male. 



The mouth is surrounded by a collar of cuticle which has a 

 median triangular prolongation on its dorsal and ventral aspects. 

 The whole collar is supported by four finger-like papillae, the 

 lateral pair supporting the apices of the triangular flaps being 

 twice the length of the median pair which maintain the basal 

 angles. 



