Vou. 2] Torrey.—Hydroids of the San Diego Region. ) 
+I 
27. Sertularella pedrensis, n. sp. 
Sertularella conica, Torrey, 1902, p. 60. 
Trophosome. Stems from creeping stolon, longest 35 mm., with 
occasional branches; stems and branches divided into slender internodes 
of variable length. Hydrothecae distant, borne at distal ends of inter- 
nodes, free for two thirds their length, narrowing to tridentate apertures, 
which are often reduplicated, with tripartite opercula; each hydroheca 
with 3 to 6 transverse rugae which are stronger on adecauline side. 
Gonosome. Gonangia ovate, covered thickly and completely with 
slender spines. 
Figs. 19, 20.—Sertularia pedrensis. Hydrotheeae. Fig. 21.— S. pedrensis. 
Gonangium. 
Distribution. San Pedro, Cal. 
The trophosome of this species so closely resembles Allman’s 
descriptions and figures of S. conica, that I formerly identified it 
with the latter. Nutting (:04) has since pointed out that the 
hydrothecae of S. conica have four marginal teeth, a fact which 
at once distinguishes the two species. The recent discovery of 
two gonangia on the San Pedro colonies affords an unmistak- 
able diagnostic character. 
