264 Transactions. 
The slide sent to me contained half a dozen hydrothecae, very well 
preserved. They are notably small for Statoplea, subconical, rather 
narrowed-in between mesial sarcotheca and margin, with a rudimentary 
ridge on adcauline side near base, from which originates a very small 
sharply-defined fold of hydrotheca-wall, curved or sigmoid ; sides are 
more prominent than front and back, and margin has small undulations 
or crenations which are quite irregular, even those on the two sides not 
somewhat incurved, which, as seen in strictly lateral view, projects quite _ 
abruptly. (The condition is thé same in H. secundus, the sides not curving — 
Anterior sarcotheca a little shorter than hydrotheca, but more pro- - 
jecting, and adnate to h drotheca rather more than half the length of А 
In a slide of portions of the “Challenger” specimen of Н. secundus, 4 
sent for comparison, are a considerable number of hydrothecae, which — 
ksi. 
: secundus, and that mesial sarcotheca in the former species is more - 
projecting. : Ee 
Whether the differences are sufficiently constant to justify the retention — 
of Н. banksi as a separate species cannot be determined until further - 
material is available. © 
Halicornaria rostrata п. sp. (Fig. 18.) d 
Hydrocaulus monosiphonie, unbranched ; hydrocladia alternate, not - 
close, one on each internode, at an angle of about 45°, both series directed | 
forward ; nodes oblique. * 
e pe — Pass sarcothecae ; back entire, adnate. ec 
1 thickened ridge opposite distal ed hydr , sometimes 
extending partly round. ae E on e ; 
ial sareotheca about as lon bo inly rising 
VM g as body of hydrotheca, ташу © 
from it and adnate more than half its yh y free part canaliculate, 
