PARASITIC WORMS— LE1PER AND ATKINSON. 



55 



other suckers (,s) od the head are circular, and have an externa] measurement of 0 ' 24 nun. 

 and an internal diameter of 0' I mm. Their surface is fleshy, and they are unarmed. 

 The head is succeeded by a large globular neck measuring 0*7 cm. in length and 0'5 cm. 

 transversely. In the interior two wide wavy excretory canals run toward the segments. 



Segment^. — The segments are very peculiar. There is a central portion, rounded 

 dorsal ly and cupped ventrallv. From the outer borders of each segment there is a well- 

 marked lapel or apron which crosses from either side toward the centre. It is divided 

 by a deep cleft in the middle line from, its neighbour of the opposite side. The edge is 

 crenated and suggests the machicolations on ramparts. Only in the latter segments 

 were there any genitalia, developed. The testes number 30 to 40. and are confined 

 definitely to the dorsal portion of the 

 segment. They are large and show a, 

 crenated outline. Two wide excretory 

 canals run down either side, at the junction 

 of the lapels with the segments. No eggs 

 were present in any of the segments. The 

 longitudinal muscular bands are very 

 marked. The genital pore is peculiar and 

 opens on the border oi the lapel ventrallv: 

 the pores probably alternate. The anatomy 

 of the segments is exceedingly difficult to 

 make out. 



Encysted in the Emperor Penguin, and 

 completely closed off, occur forms consisting 

 of only the head and neck (PI. I V. fig. 23). Other cysts occur (Fig. 24) in which 

 several individuals are present and the cyst is connected with the gut of the host. 

 These worms consist of a head and a varying number of flat immature segments, the 

 beginning of the genital apertures being visible on the sides. There also occur more 

 mature forms in the cysts showing the peculiar conformation of the segments. In 

 detail the heads and necks of the three forms are identical. An almost analogous 

 case is mentioned by Railliet and Henry. These parasites were obtained by the 

 French Antarctic Expedition from Pi/t/oscdis jMpua, and the authors ascribe the 

 mature form to Anomotae/ua zeden,. 



Order TRYPANORHYNCHA. 



Fam. TETR A RHYNCH IDA E. 



Tetrai-hynchus, Raid., 1 so'.). 



:>7. TetrarhywIuLH sp. (larva). (PI. V, tig. 35.) 



This interesting little Tetrarhi/uchus was collected together with some larval 

 Nematodes, encysted in the wall of the caecum of a Barracouta [Lcp/dop'u^ eauclatus) at 



