New Polychaetous Annelids From 
Laguna Beach, California 
RALPH V. CHAMBERLIN 
In a very interesting collection of annelids from Laguna Beach transmitted to me 
for study by Prof. Hilton, the apparently previously undescribed forms listed below 
are represented. As a comprehensive report on the annelids of the region to follow 
further explorations and collecting is in contemplation, I am giving here only such 
preliminary accounts of the new forms as are thought sufficient for their identification 
in the local fauna. The types of all these species are in the Museum of Comparative 
Zoology at Cambridge. 
POLY NOIDAE 
Halosydna latior sp. nov. 
A species proportionately broader over all than the usual forms of the common 
II. insignis, californica, and pulchra. It is characterized by elytra not only closely imbri- 
cated along each side but also broadly overlapping in the middle line throughout the 
length. The elytra in general are unusually elongate in an oblique direction, the long 
axis running from the outer end cephalomesad; the outline subelliptic, the caudomesal 
edge broadly convex, the opposite one a little incurved at middle. The entire sur- 
face of elytra subdensely covered with very small rounded brown nodules or tubercles; 
within the middle region, just behind the edge of the preceding overlapping elytron, 
a number of much larger paler tubercles which in the type are present on all excepting 
the last pair. Elytra extending to outer ends of parapodia. Eighteen pairs of elytra 
present. Prostomium subangularly bulging on each side, the anterior eve at the angle, 
the posterior eye removed far caudad, by about half the greatest width of the prosto- 
mium. Paired anterior prolongations of the prostomium very long, as long as the 
median length of the prostomium back to level of posterior eyes, distally clavate. Median 
ceratophore much stouter than the lateral prolongations and exceeding them by more 
than a third in length. Median tentacle long, nearly attaining end of palpi; slender, nar- 
rowing distad, only slightly thickened subapically, with the usual slender tip which is of 
moderate length. Lateral tentacles much shorter, their tips reaching only to near 
middle of light region between proximal black region and subapical black ring of 
median tentacle. Tentacular cirri resembling median tentacle in form, being narrowed 
distad with subapical enlargement slight; one or two fine setae emerging from 
a small nodule at distal end of parapodium proximad of tentacular cirrus. The 
notocirri in general have the same characteristic form as the tentacular cirri, narrow- 
ing continuously distad with the subapical enlargement slight. First neurocirrus very 
elongate, surpassing the parapodium. ‘The other neurocirri slenderly cylindroconical, 
narrowed into a slender tip and a little narrowed proximally; attached well toward 
base of parapodium the end of which they fail much of attaining. A characteristic 
feature is the elongate form of the nephridial papillae, these in the type as preserved 
heing mostly near three times as long as thick at the middle. Neuropodial setae dark 
amber colored, numerous, arranged in two continuous regions, a narrow dorsal one 
and a much broader ventral one in the latter of which the setae form four distinct 
longitudinal series with five or six setae in each series. Notopodials moderate in 
