1905-6.] Echinorhynchus antarcticus and its Allies . 
437 
“Scotia” Collections. On Echinorhynchus antarcticus. 
n. sp., and its Allies. By John Rennie, D.Sc., 
University of Aberdeen. Communicated by Wm. S. Bruce, 
Esq. (With a Plate.) 
(Read March 5, 1906.) 
The form described in the present paper was found amongst the 
contents of the stomach of a Weddell seal (Leptonychotes weddelli), 
taken by the Scottish National Antarctic Expedition in Scotia 
Bay, South Orkneys. In all about sixty specimens were collected. 
They occurred unattached amongst material in a semi-fluid con- 
dition, so that it is not possible to state definitely whether the 
seal or some animal upon which it fed is the normal host of this 
parasite. This question, however, in the case of the Echinorhynchi, 
appears from the work of de Marval * to be one of minor im- 
portance. He has shown that in the Echinorhynchi of birds there 
is a most marked absence of specialisation of hosts, and quotes 
from other authors various instances of the same parasite occurring 
in different vertebrate classes. The worms in the present case 
showed no indication of having been affected by the digestive 
juices of the seal. As will appear from the description given 
below, their structural peculiarities suggest relationships with 
certain forms known to inhabit aquatic birds. 
External Features. 
The most striking peculiarity in the structure of this parasite is 
its external form. This has a marked resemblance to an ordinary 
pipe with a very short stem and adorned with a somewhat fan- 
tastic lid (fig. 1). Three regions are distinguishable — the 
rostrum and two body-divisions. Of these, the anterior bears 
spines regularly distributed over its whole surface ; the posterior 
is spiny only in part. The former further differs in shape, being 
* Revue Suisse de Zoologie, tome 13, fasc. 1, pp. 195-387. 
