H. A. Baylis 
369 
Hosts of the larval form, “Ascaris capsularia.” 
A long list of fishes is given by Stossicli (1896, p. 58) as hosts for this 
“species,” but unfortunately it is impossible to decide how many of 
the cases mentioned by him were really A. capsularia, as now defined, 
and how many represented other immature forms. All that it is 
possible to do at present, therefore, is to give a list of the fishes from 
which I have personally examined specimens that conform to the 
description given above, and which I regard as A. capsularia, sensu 
stricto. These represent, probably, only a very small fraction of the 
hosts of this apparently abundant and widely-distributed form. 
The list is as follows: 
Host 
Previous determination of parasite 1 
Aplianopus car bo 
(1) A. capsularia Rud. 
(2) and (3) Agamonema commune Dies. 
Clupea alosa 
Agamonema capsularia Dies. 
Clupea harengus 
Ascaris, sp. 
Coitus scorpius 
Ascaris constricta Rud. 
Gadus callarias 
Agamonema commune Dies. 
Lampris luna 
None. 
Merluccius, sp. 
Agamonema capsularia ? Dies. 
Molva molva 
Agamonema commune Dies. 
Motella mustela 
Ascaris capsularia Rud. 
Plcuronectes pesus 
Ascaris collar is. 
Salmo salar 
Agamonema commune Dies. 
Sciaena aquila 
Ascaris constricta Rud. 
Sebastes norvegicus 
None. 
Sphyraena, sp. 
Ascaris sphyraenae. 
History of the parasite in its final host. 
It seems probable that the stage of development at which the larvae 
are swallowed, along with their first host (a fish), by their final host 
(a seal) makes little difference to their subsequent history. 
Stiles and Hassall (1899, p. 117) give as the length of the immature 
forms from the stomach of the fur seal, 14 mm. or more. Yon Linstow 
(1900, p. 119) describes immature forms, which he refers to A. decipiens, 
as living in dense masses in the stomach of the walrus (Odobenus 
rosmarus) and Phoca barhata. These larvae measure, according to 
1 It should be understood that I do not imply that all the names under this heading 
are synonyms of A. capsularia, but merely that these various names have been attached 
to specimens of that form. It is probable that some of the names are synonymous, but 
in order to prove this it would be necessary to re-examine the types. 
