2 Journal of Entomology and Zoology 
number, the dorsal ones short, the most ventral long, attaining the end of the neuro- 
podium. The elytra are greyish with dusky or brownish mottlings. Notocirri with 
dark annulations as usual. 
Length, 42 mm.; width to end of setae, 14 mm.; to end of parapodia, 10.8 mm.; 
exclusive of parapodia, 7 mm. 
Taken on Laguna Beach at Mussel Point (Hamilton coll.). 
Type—M. C. Z. 2, 138. 
Halosydna tuberculifer sp. nov. 
Among other forms known from the California coast characterized especially by 
the strong tuberculation of all the elytra. The tubercles are mostly large and conical 
though some are rounded and are confined chiefly to the mesocaudal half and median 
region of each elytron, a series of large ones ordinarily present along the caudal and 
caudomesal margin; in the first two or three pairs of elytra the tubercles of the 
median region especially large, the tubercles on the first pair occurring on the anterior 
part as well; ectal margin of elytra strongly fringed or ciliate. Elytra in general 
subcircular but with margin of ectocephalic side flattened or in part a little incurved. 
Elytra in contact or nearly so at median line but not there at all overlapping. Pairs 
cf elytra eighteen, these being present on somites II, IV, V, VII, IX and so on alternate 
ones to XXV and then on XXVI, XXVIII, XXX, XXXI, and XXXIII. The last three 
setigerous somites bear notocirri. Anterior pair of eyes near middle of length of 
prostomium proper, larger than posterior pair which are a little closer together and 
are well removed from the others. Lateral prolongations of the prostomium in front 
which bear the lateral tentacles only a little shorter than the median ceratophore 
though much more slender. Median tentacle shorter than the palpi, moderately en- 
larged and strongly rounded subapically and with the usual slender tip or filament 
which is comparatively short. The lateral tentacles of similar form but much shorter 
and more slender. Neurocirri of first normal segment large, resembling a notocirrus. 
The other neurocirri much shorter, subconical, constricted at base and prolonged into 
a slender but short tip; attached near base of neuropodium in each case. Anal cirri 
similar to notocirri but much longer and stouter. Neuropodial setae of usual general 
form, amber colored with dark tip, arranged mostly in two or three, usually uneven, 
subvertical series. The notopodial setae fine, numerous, the longer ones not falling 
much short of or reaching the ends of the neuropodials. The nephridial papillae oc- 
cupy the ordinary position; they are small and unusually short. The color of the 
elytra uniform greyish brown. Antennae, tentacular cirri and notocirri banded at 
base and distally with black. 
Length, 23 mm.; width exclusive of parapodia, 3 mm. A little narrowed cephalad, 
somewhat more so caudal. 
Taken at Laguna Beach under stones. (1917) 
Type—M. C. Z. 2, 139. 
Halosydna letoseta sp. nov. 
Body strongly and continuously narrowed caudad. Prostomium wider than long, 
deeply bilobed, the median tentacle inserted deeply in the intervening incision. Lobes 
extended forward into peaks which, however, are constricted at base so as to give 
appearance of more or less distinct ceratophores, these short. Anterior eye free on 
each side, the caudal one much farther mesad and overlapped by the peristomium. 
Tentacles short, the median line a little longest and about equalling the palpi; in 
