8 PROCEEDINGS OF THE NATIONAL MUSEUM, VOL. 62. 
ing, rarely oval, rarely quadrilocular, and with an outer band of 
smaller loculi, the appearance varying somewhat according to point 
focused upon, the dorsal pores of this type somewhat smaller than 
those occuring ventrally; the first type in indistinct clusters appar- 
ently confined to the body margin region in contrast to some other 
species, the second scattered very abundantly over the whole surface, 
but more numerous toward the margin than in the middle of the body, 
both dorsally and ventrally, the ventral disk pores in the region of 
the genital opening with oval and not trilocular centers; in addition 
te the preceding with numerous larger clear disk pores, unequal in 
size, arranged in transverse rows across the center, a single row to a 
segment on the thorax as well as the abdomen, these presenting much 
the same appearance as the ventral cicatrices of other genera except 
for the small size and much greater number; apparently without long 
trilocular pores in middle portion of body; derm near middle of body 
with small slender setae, each set in a conical collar, stouter, longer 
setae, also set in conical base, and long tapering, straight or very 
slightly curved, acutely pointed spines, each somewhat enlarged at 
base but without collar, these last somewhat stouter dorsally than 
ventrally, and gradually increasing in size and length toward the body 
margin on both surfaces, the setae increasing rapidly, some on the 
body margin relatively very long and slender; in addition along body 
margin with indefinite clusters, one to a segment, of smaller, more 
lightly chitinized, more swollen and usually distinctly curved spines 
without any sort of definite collar at base; most but not all of these 
on the abdominal segments; these spines probably corresponding to 
the stout, lanceolate spines of the derm of the genotype; spine meas- 
urements of this species, in microns, as follows: Mid-dorsal, shortest, 
53; longest, 68; mid-ventral, shortest, 46, longest, 78; marginal, long- 
est, 132; curved spine, average, 36; with a cylindrical anal tube having 
a heavy band of irregular wax pores at its inner end; ventral cicatrices 
discussed under derm pores; the actual density of the setae and pores 
apparently varying in this species as in others according to the degree 
of distension of the body as a result of the development of the ovaries. 
Larva.—tKssentially like that of M. fuscus in shape and other char- 
acteristics; antennae more elongate, 5-segmented, the third sometimes 
with faint indications of a division; legs long and slender, tip of claw 
with three indistinct denticles; digitules less than half length of the 
claw, with two pairs of large thoracic and seven pairs of relatively 
minute abdominal spiracles, all without pores; derm with some lon- 
gitudinal rows of trilocular, rarely quadrilocular, disk pores dorsally 
and submarginally ventrally, and with a marginal series of 14 pairs 
of large trilocular tubular pores instead of 13 as in fuscus, with five 
longitudinal hands of lanceolate spines. one median, two marginal, 
