368 
Ascarids in the British Museum 
body-wall on the dorsal side. I have not seen an instance of the 
presence of a backwardly-directed oesophageal caecum, although 
Jagerskiold (1894) and Stiles and Hassall (1899) have both stated that 
such a caecum is occasionally present, and have figured examples of it. 
The ventral excretory gland exhibits essentially the same features 
as in the larval forms, being a flattened, ribbon-like cell lying along the 
inside of the body-wall for about the anterior third of the body. At its 
widest part it measures slightly more than 1 mm. At the level of the 
junction between the oesophagus and chyle-intestine, and the base of 
the intestinal caecum, it narrows rather rapidly, but still runs forward 
quite distinct from the body-wall. Its duct merges with the mid-ventral 
“field” of the latter at about 1 mm. from the head-end, opening, as 
described by Stiles and Hassall, between the ventro-lateral lips. 
Systematic Position. 
In their preliminary report on the Parasitic Worms of the Terra 
Nova Expedition, Leiper and Atkinson (1914, p. 226) have instituted 
a new genus, Terranova, for an Ascarid from the stomach of a shark. 
The following features mentioned in the diagnosis of the type- 
species, Terranova antarctica (1914, p. 226; 1915, p. 28) are of interest 
in connection with Ascaris decipiens: “ Three squat fleshy lips with 
paired anterior lobes. No labia intermedia. Oesophagus without 
appendage. The intestine has a long caecum.” Further, the oeso¬ 
phagus “enters the intestine laterally,” though no mention is made of a 
specialized posterior division similar to that seen in A. decipiens. The 
excretory organ is not mentioned. The authors do not attempt to 
include any of the previously-described species of Ascaris in this new 
genus; but they have created another, Kathleena (1914, p. 226), in 
which they include (1915, p. 27) “ Ascaris'’’ osculata Rud., “A.” radiata 
v. Linst., and “A.” rectangida v. Linst. This genus differs from 
Terranova chiefly in having interlabia and a solid oesophageal 
appendage. 
If the anatomical features mentioned are to be considered sufficient 
grounds for the separation of these two genera from each other, and from 
Ascaris itself, it would seem likely that Ascaris decipiens will have to 
be included in Terranova. But probably it will be found that other 
species of Ascaris agree with one or the other of the new genera, and 
the re-examination of such forms would throw much fight on the 
question. For the present, at all events, I prefer not to press the point, 
but rather to retain the older generic name for Ascaris decipiens. 
