SYNOPSES OF NORTH-AMERICAN 
INVERTEBRATES. 
XIV. THe Hypromepus& — Part II. 
CHAS. W: HARGITI. 
THE CAMPANULARIÆ (CALYPTOBLASTEA). 
Tue Campanularie are distinctively colonial Hydromedusæ, 
many of them most exquisitely beautiful and graceful forms. 
In size they vary from very minute forms barely visible to the 
unaided eye, to forms like Halecium, measuring from twelve 
to twenty inches or more in height. The hydranths are provided 
with specialized receptacles, hydrothecæ, into which they are 
capable of more or less complete retraction. Gonophores are pro- 
duced by budding, and are provided with specialized receptacles, 
‘gonangia, similar in morphological features to the hydrothecæ. 
The gonophores may be liberated as free medusa, or may 
remain fixed as medusoids, the sexual products maturing within 
the gonangium and later escaping as free larvae or planule. 
When free, the medusze are known as Leptomedusz, charac- 
terized generally by a low, flat bell, marginal sense organs 
usually of the vesiculate type, with the gonads usually borne 
along the underside of the radial canals. 
A classification of the Campanularida is almost, if not quite, 
impossible without the presence of the gonosome, which in 
many genera is the most distinctive differentiating feature. 
In the following synopsis this feature will be in constant requi- 
sition, and where it is absent in specimens the student is admon- 
ished as to the doubtful character of purely morphological 
determinations. 
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