H. A. Baylis 259 
characterised by the possession of an oesophageal appendix, but no intestinal 
caecum. 
From this survey it appears doubtful whether the subfamily Hetero- 
cheilinae, as it stands, can be regarded as a satisfactory or natural group. 
We have seen that Crossophorus probably ought to be removed to a position 
by itself. The genera Hcterocheilus, Typhlophorus and Goezia (= Lecano- 
cephalus) also seem to be clearly marked off from the rest of the forms by 
peculiarities of external features—all the remainder being of typical “ Ascarid ” 
appearance externally. 
There can be little question that. Terranova is generically identical with 
Porrocaecum, and Kathleena with Contracaecum. Hence, according to the law 
of priority, the names Terranova and Kathleena fall into synonymy. 
Setting aside all the aberrant forms mentioned above, the only genera 
among the original Heterocheilinae with which we are immediately concerned 
are Porrocaecum , Contracaecum and Raphidascaris. These genera, together 
with Anisakis, and with the addition of certain other forms to be mentioned, 
seem to compose a more natural group, united by possessing the general 
outward appearance of an “Ascaris,” but with certain modifications of the 
alimentary canal which mark them off from the Ascarinae. 
Proposed new arrangement. 
The new group which it is proposed to set up comprises the type-genus of 
the former subfamily Anisakinae and part of the former subfamily Hetero¬ 
cheilinae. The forms which are to be included in it may be divided into two 
sections, according to the presence or absence of a specialised “ ventriculus,” 
forming a posterior division of the oesophagus. This structure, for which 
Dujardin’s term may conveniently be used, has been neglected since his time 
as a feature of systematic value. It seems to the writer, however, that it 
deserves the consideration which Dujardin was disposed to give to it, and 
that it is probably of greater phylogenetic importance than the presence or 
absence of caecal appendages. Although no special attention has as yet been 
devoted to the ventriculus of Ascarids from the histological or physiological 
standpoints, it is interesting to observe that in a nematode of another family, 
Camallanus, in which a very similar organ exists, a recent writer (Magath 
(1919)) has suggested that it is concerned in the excretory processes. In the 
species dealt with it seems to have some structural connection with the 
excretory apparatus. Now in some of the Ascarids in which a ventriculus 
occurs we find it associated with a peculiar type of excretory apparatus, 
terminating in a long, unpaired, unicellular “gland,” opening close to the lips. 
This is the case, at all events, with a number of the forms included here 
under the names Anisakis, Porrocaecum and Contracaecum, and will very 
possibly be found to be characteristic of all the forms in which there is a 
ventriculus. Pending fuller investigation, therefore, it is suggested that all 
