Entozoa from the Murman Coast. 513 
present, usually in considerable numbers, in all the erder- 
ducks examined. 
An entire specimen measures } to 13 cm. in length, with a 
maximum width of 0°36 mm. ‘The scolex (fig. 8,A) is 
flattened dorso-ventrally, and measures 0°22-0°27 mm. across 
at the suckers and about 0°15 mm. in thickness dorso- 
ventrally. ‘lhe suckers are very large, meeting in the middle 
line. The rostellum is long, slender, and _proboscis-like, 
measuring about 0°35 mm. in length when fully extended. 
At the end it expands into a bulb. The hooks (fig. 8, B), 
which were only seen in specimens with the rostellum 
retracted, are ten in number and measure 65 w in total length. 
They are of an unusual shape, having a very long “ dorsal” 
and a greatly reduced “ ventral” root. 
Segmentation begins close behind the scolex. In a com- 
plete specimen there are some three hundred segments, which 
are broader than long throughout. ‘The cirri, which are 
usually extruded, are spiny, and, when fully extended, 
measure about 0°05 mm. in length. The onchospheres 
measure about 20 w in diameter. 
Of the species of Aploparaksis |itherto recorded from 
Anseriform birds, this species is easily distinguished from 
A, furcigera (Rud.) and A. birula2, v. Linst., by the size and 
shape of its hooks. The hooks of A. fuligulosa, Solowiow, 
1911, are undescribed, but the latter form has a smaller 
scolex and much longer cirri, among other points of difference. 
The description of A. elise, Skijabin, 1915, I have unfor- 
tunately been unable to consult. A. cérrosa (Krabbe), 
which occurs in Lariformes, has hooks only 22 w in length. 
NEMATODA. 
Ascaride. 
Ascaris capsularia, Rud. 
Hosts: Cottitd fishes. Yukanski, June 1917. 
This immature Ascarid, according to views put forward 
elsewhere by the writer*, is the larval form of Ascaris de- 
cipiens, Krabbe, which occurs as an adult in seals. The 
young forms are found in fishes of various genera and 
families, usually coiled up like watch-springs in capsules 
under the peritoneum. 
‘The present examples came from various Cottid fishes, the 
precise determination of which is unknown, They agree in 
almost all respects with the description previously given *, 
* ‘Parasitology,’ viii. no. 3, 1916, p. 360, 
