CALKINS: SOME HYDROIDS FROM FUGET SOUND. 339 
Hineks); Greenland (Sabine); Grand Manan and Eastport, Me. 
(Stimpson); Massachusetts Bay (L. Agassiz). 
Atractylidae. 
Perigonimus Sars. 
\ 
Coenosarc sheathed in a chitinous polypary, stem branching or 
simple, rooted by a thread-like stolon ; polypites fusiform with a 
single verticil of filiform tentacles round the base of a conical pro¬ 
boscis; gonophores developed from the coenosarc. (Hineks.) 
3. Perigonimus repens T. S. Wright. Pl. 1, figs. 8 , 3a, 3b, 
3c, 3 d. 
Atractylis repens (Wright). Perigonimus pusillus (Allman). 
Perigonimus repens (Allman). 
Stems simple, erect, about 6 mm. high. Hydranth club-shaped, 
white, partly retractile into tube, tentacles 10 to 12. Gonophores 
pedicilate and borne on the stems. 
In the Puget Sound form the stem of the gonophore is very long 
and the character is constant. The difference in length, however, 
does not seem sufficient to raise the form to an independent species. 
Habitat. Found covering the back of the carapace and the 
appendages of a species of Pisa, dredged in Townsend Harbor. 
W right describes it as growing on the Sertularians and upon the 
spider crab in the Firth of Forth, Alder on Pentalium entalis and 
other shells; and Allman on the operculum of Turritella communis 
in Shetland. 
CALYPTOBLASTFA or THECATA. 
The bulk of Pacihc coast hydroids is made up of thecate forms. 
In the region of Puget Sound these do not impress one as being- 
very abundant, due probably to the absence of many large branch¬ 
ing forms like Obelia and Laomedia. Most of the thecates belong to 
Campanularia or allied genera which do not grow to large colonies. 
At Sitka, on the other hand, the piles and rocks are covered with 
great forests of Obelia and related forms, and one is impressed with 
their abundance. In regard to the smaller forms at Sitka I cannot 
speak. The Calyptoblastea have been a difficult group to deal 
with, and, as time goes on, the task becomes more difficult. This is 
