18 THE HYDROIDS. 
, 
like opening in every respect like those of the pinna-bearing tube on which? 
there are 12 to 14 nematophores between each two adjoining pinnae. 
Gonosome : — Not present. 
Habitat : — Station 4630. Latitude N., 6° 52’. Longitude W., 81° 42.5" 
Depth, 556 fms. 
There are 6 tubes showing in surface view of the base of the main stem, 
hence there must be at least 12 in it, and these apparently all come fron 
the hydrorhiza. The hydrotheca-bearing tube disappears at the base under 
some of the simple tubes. 
This species is nearest to C. dolicotheca Allman and C. flexuosus Nutting, 
but differs from them both in the compound character of the main stem, the 
nodal joints of the pinnae, and in the structure and the arrangement of the 
nematophores. Neither are there any “imperfect septa (septal ridges)” in 
the parts of the stem at the backs of the hydrothecae. 
Plumularia helleri Hincks. 
Plate 15. 
Two colonies of this delicate Plumularian attached to a large spicule of a 
siliceous sponge were collected in the Gulf of Panama; one at Station No. 
4621; Lat. N. 6° 36’, Long. W. 81° 44’, depth 581 fms.; and the other at 
Station No. 4622, Lat. N. 6° 31’, Long. W. 81° 44’, depth 581 fms. 
A slight difference in the two specimens is noticed in the position of the 
hydrothecae on the internodes: in the specimen from Station 4621 the inner 
part of the rim of the hydrotheca is on a level with the node; in the other 
specimen the rim is below the node. 
Aglaophenia struthionides Murray 
Plate 10, figs. 4-6. 
A single stem of this beautiful species, with several corbulae, is from 
Station 4643. Depth, 100 fms.; bottom, broken shells and Globigerinae. 
Locality about 4} miles southwest by south from the west end of Hood 
Island, Galapagos Archipelago. 
In several collections I have had from the Pacifie Coast of the United 
States, this has been the most abundant species. This extends the range of 
Puget Sound to San Diego, southward to the Galapagos. It was deseribed 
by Murray in 1860 as Plumularia struthionides, and by Clarke in 1876 as 
Aglaophenia struthionides. 
