26 University of California Publications. [ ZooLocy 
Sertularella halecina is at once a typical Synthecium in the 
character of the hydrothecal margin and the intratheeal origin 
of the gonangia, a typical Thecocladium in the intrathecal origin 
of the branches, a typical Sertularella in the manner of the origin 
of both branches and gonangia. Allman refers to the intrathecal 
origin of two branches in Synthecitum campylocarpum as an 
abnormality, and Nutting speaks similarly of the intrathecal 
origin of the only two branches which were present in the mate- 
rial from which I deseribed Sertularella dentifera. Both cases 
may be abnormal, in the sense of unusual; but in the light of 
conditions in S. halecina, is it wise to dismiss them forthwith as 
taxonomically insignificant? Which are the abnormal, the insig- 
nificant characters in S. halecina? I must confess my inability 
to decide. Until such a decision be reached, I do not think better 
can be done than to consider the species a member of the Sertu- 
larella group, in which it was originally placed. 
Sertularella group. 
26. Sertularella halecina. 
Sertularella halecina, Torrey, 1902, p. 61, p. 6, fig. 55. 
Trophosome. Stems from a creeping stolon rise to height of 30 mm., 
with few branches which originate either within hydrothecae or just below 
them. Nodal divisions faint, often wanting. Hydrothecae adnate at base 
only, cylindrical, with slight swelling on lower side of base, wide aperture 
with smooth, everted rim. 
Gonosome. Gonangia arise within hydrothecae or from stolon, long, 
tubular; single tubular gonophore. 
Distribution. San Diego Bay, 3 to 12 fathoms; growing on 
kelp and among bryozoa. Gonosome present, July, 1901; June, 
July, 1903. 
My reasons for withdrawing this species from Synthecium, 
where Nutting placed it, have been given above. I am not yet 
prepared to consider it identical with S. cylindrica Bale (Nut- 
ting, :04), because there is no record of the method of origin 
of branches and gonangia in the latter, and the margins of the 
hydrothecae are not so distinctly or characteristically everted. 
