14 Journal of Entomology and Zoology 
long; weakly longitudinally ridged and densely finely papillose. Body strongly nar- 
rowed from the anterior region caudad, the caudal end slenderly pointed. Segments 
biannulate. Number of segments in the type near one hundred and thirty. 
Length, 26 mm.; width, 1.5 mm. 
Type—M. C. Z. 2, 158. 
Balboa, December 26, 1917. 
Glycera basibranchia sp. nov. 
Resembles exigua in having the branchiae in the form of a series of single, simple 
filaments but readily distinguished in having each branchia attached at base of para- 
podium on the dorsocaudal surface just ectad of the notocirrus instead of at the distal 
end above. The branchiae begin on the twenty-ninth setigerous somite and continue 
to about the one hundred and twenty-ninth, decreasing in size at the two ends of the 
series. In the middle region they are cylindrical, distally rounded, and transparent, 
and at most do not surpass the distal end of the parapodium, most of these being obvi- 
ously shorter than this in the preserved specimen. Also decidedly different from 
exigua in having four lobes at the distal end of each parapodium, two postsetal and 
two presetal. These are narrowly triangular, distally pointed, with the presetal lobes 
thicker and more conical and decidedly longer than the postsetal. The short, distally 
rounded notocirri are attached at the base of the parapodia above in the angle between 
the latter and the body wall. Neurocirri distally subeylindric, resembling the distal 
parapodial lobes. The prostomium disinctly ringed to near middle, the basal half 
showing five rings while the distal half in the type is only vaguely annulate, though 
with indications of apparently seven nearly fused rings, making the total number 
twelve. Proboscis long, densely papillose. Type incomplete caudally; one hundred 
and forty-five segments retained. 
Length (not quite complete), 36 mm.; greatest width, 1.3 mm. 
Type—M. C. Z. 2, 159. 
A note gives the color in life as light, the red blood showing through as usual in 
the family. 
Glycera verdescens sp. nov. 
A very small form differing from the two preceding in wholly lacking branchiae. 
The parapodia are strikingly different in that the postsetal lobe is either wholly absent, 
as in anterior region, or is represented by a single, small, pointed process, while there 
are two presetal lobes which are long and subcylindrical or finger-like and of which 
the ventral one is ordinarily the larger. The notocirrus is small and occupies the 
usual place in the angle between the dorsal surface of the parapodium and the body- 
wall. Neurocirrus slenderly conical, darkened distad as are also the presetal lobes. 
The slenderly conical prostomuim showing twelve annuli. Type at present showing a 
distinctly greenish tinge. Type incomplete caudally, sixty-nine segments retained, the 
length being 13 mm., width, 1.1. mm. 
Type—M. C. Z. 2, 160. 
ARICIID 12 
Nainereis hespera sp. nov. 
This is apparently a smaller species than /onga or robusta and is composed of 
fewer segments. It differs from those species in having the anterior division of the 
body composed of only nineteen segments and in haying the first branchie appear on 
