342 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
ciidiie never have a free stalk, the Campanulariidae invariably; 2, 
because the hydrothecae of the latter family are never so reduced as 
those of the former; 3, because the branching of Haleciidae is never 
regular like that of the Campanulariidae but more nearly resembles 
that of the Athecata, being midway between the racemose type of 
the Gymnoblastea and the cymose type of the Calyptoblastea. 
The smallness of the cup is better explained as a primitive than as a 
differentiated character, approaching closely to the type of cup 
formed by the enlargement of the chitinous periderm under the 
hydranth of many athecates, and into which some forms can partly 
retract. This is strikingly shown in Ilalecium macrocephalum 
Allman (’77), a form in which the theca is represented by only 
a sessile, narrow, membranous lip. Furthermore an additional point 
is seen in the peculiar character of the female gonophore and 
proliferating blastostyle mentioned above, which again shows atlie- 
cate affinities. 
The comparatively small family of Haleciidae is therefore of con¬ 
siderable phylogenetic importance and for the present at least may 
be regarded as the nearest approach to the gymnoblastic liydroids. 
Comparatively few Haleciidae have been found in North Ameri¬ 
can waters, while those which have been found on the Atlantic 
coast, according to Agassiz, appear to be confined mainly to the 
most northern waters. II. halecinum (Johnston) has been found 
in Greenland (Fabricius), on the northern coast of Maine (A. E. 
Verrill), and Massachusetts Bay (L. Agassiz). II muricatum Ellis 
and Solander is reported from Nova Scotia (Anticosti expedition), 
from Eastport and Grand Manan (A. E. Verrill). On the Pacific 
coast, Clarke reports II tenellum (Hincks) from San Diego, Cal., 
II. halecinum from Unalaska, Alaska, II. plumularoides from 
Nunivak Island, and II. scutum (Clarke) from Semidi Island to 
Unalaska. 
Hydrocaulus unbranched, slightly, or much branched, hydranths 
without free stem, usually regularly and alternately arranged, 
hydrotheca flat, shell-like, never large enough to take in the 
hydranth, and without operculum. Sporophores. Female blasto¬ 
style a slightly reduced double hydranth, male blastostyle greatly 
reduced. 
