36 University of California Publications. [ ZOOLOGY 
some in D. mirabilis. Bale, however, is certainly in error in 
finding in Jickeli’s Kirchenpaueria the bond of union. Accord- 
ing to Jickeli’s figure (783, pl. 28, fig. 27), the hydroid for which 
he erects the genus is an eleutheroplean plumularian—probably 
a Plumularia-—with nematophores broken away. The frequent 
absence of nematophores ir species which characteristically pos- 
sess them and the absence of any other distinguishing characters 
remove the slender claims to priority over Diplocheilus which 
have been made for this inadequate genus. 
Diplocheilus allmani, n. sp. 
Halicornaria producta, Torrey, 1902, p. 75, pl. 10, fig. 95. 
Trophosome. Colony with simple stem, divided obliquely into inter- 
nodes which vary in length according to age. Hydrocladia alternate, each 
from a shoulder process projecting from the middle region of each inter- 
node. Each hydrocladium divided more or less obliquely into equal 
thecate internodes. Each hydrotheca somewhat compressed below, some- 
what flaring distally, with a broadly oval, smooth orifice; about as deep 
as long; free for one third of its length. Strong anterior intrathecal sep- 
tum about two thirds the length of the hydrotheca from the bottom, 
reaching about one third across it at widest point. Cauline nematophores 
absent with the exception of single axillary nematophores. Mesial nemato- 
phore short, not reaching the base of hydrotheca, expanding into the 
form of a sickle shaped segment of a saucer with a diameter two thirds 
that of hydrotheca and embracing the internode for half its circumference. 
Single median supracalycine sarcostyle, flanked by two webs of perisare 
stretched between theca and internode, forming a non-typical median 
nematophore. 
Gonosome absent. 
Distribution. Pt. Loma, Cal., on seaweed and sponges. 
The differences which separate D. mirabilis Allman, D. pro- 
ducta (Bale) and D. allmani are slight. D. allmani, originally 
thought to be identical with D. producta, possesses hydrothecae 
with flaring rims and broadly ovate apertures instead of the 
compressed form and narrowed apertures of D. producta. It 
differs from D. mirabilis in the absence of all cauline nemato- 
phores save those in the axils of the hydrocladia, and the cauline 
internodes never bear more than one hydrocladium each. The 
immaturity and paucity of my material make it impossible to 
determine the real value of these differences. For the present, 
then, it seems desirable to distinguish the species. 
