CHARACTERISTIC DEEP-SEA TYPES. — ACALEPHS. 135 
by the “Blake.” In its affinities, Gleba is one of the most 
problematical of all the siphonophores. Like the physophores, 
it has two rows of nectocalyces, but no 
true float or covering seales. Moreover, 
in the physophores the nectocalyces nearest 
the float are the smallest and the last to 
form, while those at the opposite end are 
larger. In Gleba the bells at the anterior 
extremity are fully formed, while those at 
the posterior end are least developed. 
We have two or three species of a dis- 
tinct group of siphonophores, known as the 
Calycophore, one of the most common of 
which is Diphyes acuminata. (Fig. 430.) 
Another species, belonging to the genus 
Epibulia, was also collected ; it is similar 
to a Mediterranean species, and is probably 
the same as that recorded from the coast of 
Greenland by Leuckart. "The genus Aby- 
la, A. trigona, was found in the Caribbean 
Sea, and fragments of a large Praya were 
observed near the Tortugas. I have al- 
ready alluded to this group of siphono- VO 
phores as driven into Narragansett Bay Fr. N 
during the summer. " E 
The first extensive report on deep-sea (DN 
hydroids was based upon the collections | A 
made by Pourtalès in the Straits of Florida. È : 
They are deseribed by Professor Allman, Wd 
in one of the most important memoirs ever 
published on this group. The subsequent 
explorations of the ** Blake" added a num- 
ber of genera possessing most important 
morphological characters. As has subse- 
( 
quently been found in other collections of 
deep-sea hydroids, a majority of the genera s 
collected belong to the Plumularide. A spe- _, f 
5 Fig. 430. — Diphyes acu- 
cies of the genus Aglaophenia (A. crenata) minata 4. (Fewkes) 
