Barz.—Hydroids from the New — Coast. 255 
supporting a small branch close to the top. These branches are arranged 
in an irregular spiral, are mostly under lin. in length, and sometimes 
give origin to one or two secondary branches. The structure of each 
individual branch corresponds closely with that of a complete shoot of 
P. setacea, the hydrothecae and sarcothecae, with 
internodes of branches may be very irregular, the 
result apparently of repeated regenerations. 
Professor Chilton's specimens were very small 
pieces, not including more than lin. of stem. 
T 
converging towards each other in axil), and two 
in line, one about one-fifth and the other about 
three-fifths of the length of internode from base. 
In the original specimen I had not observed 
these sarcothecae, but on a close search I found 
two or three remaining, also several scars 
IS, Ета. 12. 
judging from the thick perisare, was an old Plumularia = Bale. 
i x 80. 
were lost they were not replaced (as were the 
branches), and that the channels communicating with them had been 
more or less filled up with регівате. 
Dr. MacGillivray’s specimens closely resemble erc: from New Zea- 
land, the only difference I noticed being that the s tud 1 in some 
cases supported three sarcothecae in line instead o 
Thecocaulus heterogona n. sp. (Fig. 13.) 
Shoots growing in clusters, reaching about 6 in. in height, stems stout, 
monosiphonie, unbranched, pinnate, joints very oblique, a hydrocladium 
and a hydrotheca on each internode. Hydrocladia alternate, both series 
springing from the front, CMM oblique, internodes short, a hydrotheca 
on each except the 
rothecae set at an pets of about 45°, large, campanulate, free at 
the back, free part somewhat concave, margin entire. 
arcothecae bithalamie, canaliculate, more or less movable, one on 
each side of hydrotheca (except. the cauline ones), one in front, curved 
forward, one on second bosine of each hydrocladium, two abreast above 
each cauline hydrothec 
