180 ■ BULLETIN 15 8, UNITED STATES NATIONAL MUSEUM 



fringed with small spines on their outer margins. The terminal 

 segment of the fifth legs reaches for more than half its length be- 

 yond the tip of the inner expansion of the basal segment; it is im- 

 perfectly 3-lobed at the tip and armed with three long setae, of which 

 the middle one is much the shortest; the inner expansion of the 

 basal segment is narrow, squarely truncated, and tipped with two 

 very unequal setae. Total length, 0.3-0.4 mm. 



Male. — Body a little shorter than that of the female ; cephalic seg- 

 ment quadrangular, as wide anteriorly as posteriorly; genital seg- 

 ment no longer than the first abdominal segment; dorsal claws of 

 anal segment enlarged at the base and strongly curved. First an- 

 tennae stouter than in the female, the aesthetask on the third seg- 

 ment widened and flattened and irregularly bent; second segment 

 densely setose on its anterior margin and sharply bent. Fifth legs 

 like those of the female but a little smaller. Total length, 0.28-0.35 

 mm. 



Remarhs. — This species may be distinguished by the presence of 

 the two dorsal claws on the anal segment and by the long and slender 

 first antennae. It appears to live within the sand, for it can only be 

 obtained by digging up the sand to the depth of an inch or more and 

 washing it thoroughly. Further examination will probably reveal 

 its presence in the sands of many of the other beaches within the 

 present area. 



ARENOSETELLA FISSILIS, new species 



Plate 2, m-p 



Occurr^cnce. — Four females were washed from the beach sands of 

 the Buzzards Bay bathing beach at Woods Hole in August, 1927. 

 The female holotype is U.S.N.M. No. 63422. 



Color. — Body transparent and colorless, without pigment markings. 



Female. — Body of the same general shape as in the preceding 

 species, but eight times as long as wide, and not tapered so much 

 posteriorly; cephalothorax one-third longer than the second and 

 third segments combined, projecting in rounded knobs at the anterior 

 corners outside the bases of the first antennae ; rostrum long, narrow, 

 and tongue-shaped, carried horizontally and projecting beyond the 

 middle of the second antennal segment. Fourth metasome segment 

 a little longer than the third, and much longer than the fifth; uro- 

 some two-thirds as long as the metasome; genital segment undivided 

 and one-half longer than the basal abdominal segment ; anal segment 

 a little less than twice as wide as long, its dorsal claws very different 

 from those of sinnicauda. The bases of the two claws are completely 

 fused on the midline, and not so evidently articulated with the dorsal 



