PARASITIC WORMS -LETPER AND ATKINSON". 27 



spicule there is also a hollow tube, the walls of which taper away towards the tip, thus 

 exposing the lumen. 



The arrangement of the papillae agrees exactly with the description of Railliet and 

 Henry. There are four pairs of simple papillae at the base of the acicular tip (text-fio'. 

 •J, d). After a short interval, and lying well on the ventral surface, there is a, pair of 

 large double-headed papillae (text-fig. 2, c) ; alongside these on either side commences 

 a double series ol simple papillae, which extends forward to become preana] without a 

 distinct break. These papillae continue still further in 

 single series after about the eighth paired set. On 

 either side the cuticle is raised from the body-wall 

 and flattened dorsoventrall v to form a shallow keel 

 (text-fig. '2, I)) not more than 0' 15 mm. deep. 



4. Kathleena osculata (Rud.). 



Ascaris osculata, Rud. 1802. 



A large number of somewhat immature forms of 

 this common species were found in the Sea-Leopard 

 llrlydrurc/a leptonyx) and the Crab-eating Seal (Lohodon 

 carcinophagus). Forms which appear - to be the larvae 

 of this parasite were encysted in the mesentery and 

 under the peritoneal coats of the pyloric processes and 

 in the liver of Trematomus bemacchii. The species has 

 previously been recorded in Antarctic Seals by v. Lin- 

 stow and by Railliet and Henry. 



5. Kathleena rectangula (v. Linst.). 



Ascaris rvrtmtijuhi , v. Linstow, 190(5. 



,, stenocephala, Railliet and Henry, I 'JOT. 



Hosts. — In association with the previously described 

 species, A. radiata, in the Weddell's Seal were a, 

 number of larger specimens. These have already been 

 recorded by v. Linstow as Ascaris rectangida ; and 

 about the same time by Railliet and Henry under the 

 name of Ascaris stenocepliala. 



Pan/sit,-. — Male measures 2"5 cm. Female 5 cm. 

 rigid forms. To the naked eve they appear to be large and mature forms of Kathleena 

 radiata. The general topography is the same. There are three labia, intermedia. The 

 oesophagus has an appendage and the gut has a blind anterior prolongation. The 

 papillae in the tail differ only in detail from those of A. radiata. 



The spicules are equal and measure 4*4 mm. ; thev end in a slight dilatation. They 

 are ()-()4 mm. across. The anus is 0"27 mm. from the tip of the tail. 



Fig. 2. — Kathleena radiata (v. 

 Linst.) : ventral view of the 

 posterior extremity of the male, 

 showing the characteristic 

 arrangement of the papillae. 

 a, Anogenital aperture ; h, euti- 

 cular alae ; c, paired double 

 papillae ; <1, caudal group of 

 four papillae. 



Both are stout, opaque and 



