408 
KATHLEEN H ADDON. 
H. crassi ros t ri s (Sars). — Female : Anterior portion mi- 
le nown. External portion | mm. long. Stalk very broad, 
diameter one quarter of the length of the external portion. 
Male (Larval skin): No antenna} (?) . Maxillipeds three- 
jointed. External ramus of swimming legs one-jointed. 
Habitat. — Norway, on Polynoe imparis. 
II. affinis (II. J. H.).’ — Female somewhat similar to H. 
arctiens, but double the lengtii. Body half as broad as long, 
snbovate. Egg-sacs half as broad as long, fusiform. Length of 
body 3-4 mm. Male indistinguishable from that of H. 
arctiens. 
Habitat. — Kariske Hav, Northern Siberia., on Harmo- 
t h o e b a d i a . 
There seems no reason for separating the species of 
Herpyllobius of Puget Sound from H. arctiens, first 
described by Steenstrup and Liitken; the size of the female 
seems the same, and the males appear identical. I therefore 
propose to call this species Hei’p 3 Hlobius arctiens, only 
recording as a new locality for it the west coast of North 
America., and it remains as another example of the similarity 
in the fauna of the North Pacific and Atlantic sides of 
America. 
VIII. Summary. 
(1) The female Herpyllobius is entirely without appen- 
dages, and consists of two portions united by a thin stalk. 
(2) The rounded posterior or external portion contains the 
reproductive organs and bears two large egg-sacs. In it are 
certain spaces with thick epithelium-like walls, which pro- 
bably represent the gut. 
(3) The anterior portion or root system is an elongated body 
lying within the host, and composed of vacuolated tissue pene- 
trated by a lacunar system. 
(4) The lacunar sj'stem of the root unites into a main branch, 
which runs up the stalk and is continuous with the gut spaces 
in the external portion. 
' Hansen (3). 
