256 
The Ascarulae 
The species 1 of which specimens have been re-examined at present are 
the following: 
Hosts of actual material 
Ascaris aucta Rud. 
„ decipiens Krabbe 
., depressa (Zed.) 
„ colura Baylis 
„ ensicaudata (Zed.) 
„ halichoris Owen 
„ holoptera Rud. 
,, microcephala Rud. 
„ rosmari Baylis (=A. bicolor Baird) 
„ semitcres (Zed.) 
,, serpentulus Rud. (? =A. ardeae Froel.) 
,, similis Baird 
Contracaecum spiculigerum (Rud.) 
Dujardinia helicina (Molin) 
Kathleena osculata (Rud.) 
„ radiata (v. Linst.) 
„ rodhaini Gedoelst 
„ tricuspis Gedoelst 
Porrocaecum crassum (Deslongchamps) 
Terranova antarctica Leiper and Atkinson 
Blennius viviparus, Rhombus punctatus. 
Otaria jubcita. 
Gyps fulvus, Accipiter nisus, “eagle.” 
Lophoaetus occipitalis. 
Turdus merula, T. musicus, Sturnus vulgaris. 
Dugong, sp. 
Testudo graeca, T. mauretanica, T. geo- 
metrica, T. sp. 
Ardea cinerea. 
Odobacnus rosmarus. 
Vanellus cristatus. 
Ardea cinerea. 
A seal (Antarctic). 
Phalacrocorax verrucosus, P. campbelli, P . sp. 
Crocodilus niloticus. 
Hydrurga leptonyx. 
Leptonychotes weddelli. 
Plotus rufus. 
Phalacrocorax africana. 
Anas boscas dom. 
Mustelus antarcticus. 
Among the forms just enumerated, the hosts of which include mammals, 
birds, reptiles and fishes, no example of the typical, simple, Ascarid structure 
of the alimentary canal was met with. In every case some modification of 
the oesophagus was present, or some caecum or appendage either of the 
oesophagus or of the intestine, or both. 
Five main types of structure were encountered: 
I. Oesophagus muscular throughout, opening directly into the intestine, 
without posterior ventriculus or distinct bulb. A forwardly-directed caecum 
springs from the intestine. No oesophageal appendix. Examples: Ascaris 
holoptera, A. colura. 
II. Oesophagus slender, with a more or less distinct globular bulb at the 
base. The intestine is produced forwards as a long caecum. No oesophageal 
appendix. Examples: Ascaris halichoris, Dujardinia helicina. 
III. Oesophagus with a posterior glandular portion, or ventriculus, of 
elongate or oblong shape and often bent in a sigmoid manner. No oesophageal 
or intestinal caeca. Examples: Ascaris rosmari, A. similis. 
1 The determination cannot in all cases be vouched for with certainty, though no undue 
suspicion attaches to any of the specimens. Those of Ascaris colura, A. rosmari, A. similis and 
Terranova antarctica are the type-specimens of the species in question. Those of Kathleena osculata 
and K. radiata were determined by Leiper and Atkinson, being part of the “Terra Nova collec¬ 
tion. The examples of A. decipiens had been misdetermined by von Linstow as “A. simplex Rud., 
and the present determination is the writer’s. Two out of the three sets of C. spiculigerum 
(Ascaris spiculigera Rud.), belonging to the “Challenger’ and "Discovery” collections re¬ 
spectively, were determined by von Linstow. Named specimens of Porrocaecum crassum were 
kindly supplied by Prof. Railliet. 
