PARASITIC WORMS LE1PER AND ATKINSON. 



55 



other suckers (N) on the head arc circular, and have an external measurement of ' '24 mm. 

 and an internal diameter of O'l mm. Their surface is lleshy, and they are unarmed. 

 The head is .succeeded by a large globular neck measuring ' 7 cm. in length and O'f) cm. 

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



S<-</ni,-iif.. The segments are very peculiar. There is a central portion, rounded 

 dorsallv andciipped ventrally. 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 

 liv a deep cleft in the middle line from its neighbour of the opposite side. The ed'jc is 

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

 were there any genitalia developed. The testes number :',() to 40. and are confined 

 definitely to the dorsal portion of the 

 segment. They are large and show a 

 crrnated 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 hands are very 

 marked. The genital pore is peculiar and 

 opens (iii the border of the lapel ventrally ; 

 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. IV, 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 Hailliet and Henry. These parasites were obtained by the 

 French Antarctic Expedition from Pi/ijoffCt'lin jxijuin, and the authors ascribe the 

 mature form t<> Anomotaenia zederi. 



ORDER TRYPANORHYNCHA. 

 FAM. TETRAKIIYNCHIhAK. 



T,-tnir/ii/ii<-/tt<*, Rud., IHOi). 

 :;7. Tetrarhynchus sp. (larva). (I'l. V, tig. :!. r ).) 



This interesting little Tetrarhynchw was collected together with some larval 

 Nematodes. encysted in the wall of the caecum of a Barracouta (Li'/iiilopus rum/nfiix) at 



Via. 11. Anniiiotaeniii zi/ih'r! (Baird) : anterior 

 portion of scolex. /;, hooks ; r, rostellum ; 

 , suckers. 



