HYDROIDS PROM NOYA SCOTIA 
169 
himself, in his paper on Arctic Hy droids 1 mentions a species 
that he takes to be the same but he is not sure as he did not 
find the gonosome. Later Kramp 2 for the same reason could 
not be sure of the specimens he found. All of these specimens 
were found in the Arctic or Subarctic regions. There was not 
such trouble in the case of the specimens found at Canso as the 
gonophores were numerous. When they are present they are 
so large and conspicuous that they must be observed before 
the trophosome is. The trophosome bears so much resemblance 
to that of H. tenellum that they are hard to distinguish from 
each other. When the gonosome is present such a mistake 
could not be made as the gonangium of H. minutum may be 
as much as 3 mm. in long diameter and not far from that in 
short diameter. The thickness is not so great, so that alto- 
gether its shape somewhat resembles the shell of a bivalve. 
The arrangement of the teeth or spines around the margin at 
the distal end gives it a unique appearance among the gonangia 
of the Halecidae. The gonangium of H. muricatum most nearly 
resembles it, but is not more than one-fourth of the size and 
it is spiny on the flat surfaces as well as on the margin; while 
that of H. minutum has but few spines on the margin and none 
on the flat surfaces. 
The figures show the relatively small stem and the very 
large gonangium. 
Halecium muricatum (Ellis and Solander). 
Sertularia muricatum E. andS., Nat. Hist. Zooph., 1786, p. 69. 
Halecium muricatum Hinges, British Hydroid Zoophytes, 
1868, p. 223. 
Halecium muricatum Whiteaves, Marine Invert. Eastern 
Can., 1901, p. 25. 
On ascidian stalks from 50 fathoms on the Canso Banks. 
A few specimens, well supplied with gonangia, were collected. 
Halecium tenellum Hineks. 
Halecium tenellum Hinges, Ann. and Mag. Nat. Hist., 3rd 
ser. VIII, 1861, p. 252. 
x Die Hydroiden der Arktischen Meere, 1909, p. 153 
•Report ob the Hydroids of the Denmark Expedition, 1911, p. 370. 
24853 — 11} 
