Pomona College, Claremont, California 19 
tubercles, rising high above the middorsal surface. In addition to the prominent wings 
on III there is on IV on each side a much lower ridge or wing paralleling that on 
III, this not more prominent above. Unlike those of alata. somites II and III are not 
confounded laterally but are distinct throughout. Prostomium short. ‘Tentacles mostly 
lost in type; rather slender, not long, apparently in but a single transverse series. 
Peristomium deeply excavated at middle below, the bottom of the excavation rounded 
and the peristomium produced on each side of this into the usual large lobes. The 
branchie, as in the genotype and other species, strongly asymetrically developed. The 
right anterior branchia is much the largest, the trunk very long, with the left anterior 
much smaller. Of the posterior pair, the right, unlike that of alata, is also much 
larger than the left one. In the type the sternal plates are not sharply differentiated. 
The manubriate uncini of V have the general form of those in alata, but the bulge 
below the beak is much larger and more rounded with the subrostral tooth more 
obtuse and nearer the middle of the oblique edge; beak less divergent from manubrium; 
vertex with three transverse series of denticles. The color in the abdominal region 
light fulvous, in the thoracic darker with a narrow brownish stripe along caudal 
border of each segment laterally and ventrally. Type not quite complete caudally, 
retaining eighty somites. 
Length, 36 mm.; greatest width, 2.8 mm. 
Type—M. C. Z. 2, 168. 
The wall of the tube is composed of sand and shell fragments. 
Naneva gen. nov. 
Prostomium short; with numerous tentacular filaments. Uncini avicular and of 
same form throughout. Sete beginning on third somite; tips simple. Uncini begin- 
ning on the fourth somite. No lateral foliaceous lobes on the anterior segments. 
Branchie two pairs; branched; attached on somites II and III. 
Genotype—N. hespera sp. nov. 
Differs from Thelepus and Athelepus in having the branchiew branched instead 
of simple and in having the uncini begin on IV. 
Naneva hespera sp. noy. 
The prostomium forms a prominent upper lip of which the anterior border is 
turned upward all along, leaving a deep concavity between it and the upcurving pos- 
terior fold along which the tentacles are attached. Because of their curled and tangled 
condition the precise number of tentacles was not ascertained, but is about twelve on 
each side; they are long, some when fully extended being 15 mm. in length. No eyes 
were detected in the type. Peristomium forming a lower lip of but moderate length 
with straight anterior edge; scarcely twice as long as the second somite below. First 
branchia on each side attached to second somite just in front and mesad of the first 
setigerous tubercle. The second branchia attached just caudad of the first on the 
caudal region of somite III. Both branchie very similar, each presenting three prin- 
cipal branches of which the most mesal is largest; ultimate branches numerous, rather 
short. Capillary sete beginning on III and continuing to XXVII. The anterior 
setigerous processes are in the form of vertical plates with straight truncate, distal 
edge; but in going caudad these become reduced finally to slight tubercles, with the 
first about equal to half the intervening space and by the seventh equal to this space, 
while in the abdominal region the opposite series are separated merely by the median 
furrow. Anterior ventral plates strongly longitudinally furrowed. Capillary sete 
