256 BULLETIN 15 8, UNITED STATES NATIONAL MUSEUM 



the length of the terminal segment and carries a long and slender 

 inner seta. The second endopod is 1-segmented and less than half 

 the length of the basal exopod segment; the apical spine of the 

 exopod is considerably enlarged and turned inward at right angles 

 to the long axis of the exopod. The endopod of the third leg is 2- 

 segmented, the basal segment very short, the distal segment ending 

 in a short blunt spine, with a much longer spine on the inner margin 

 near the center; this latter spine is dark reddish brown and quite 

 conspicuous. The endopod of the fourth leg is very short but dis- 

 tinctly 2-segmented and tipped with two unequal short setae, with 

 two other elongate setae on the posterior surface. The fifth legs are 

 simple divergent laminae, each tipped with a long stout spine, with 

 a short spine on either side of it at its base, and four slender setae 

 on the outer margin. Total length, 0.75-0.85 mm. 



Remarks. — This species can be recognized by the peculiar caudal 

 setae and the fifth legs, and it has never before been found outside 

 of the Scottish and Norwegian coasts. 



EMERTONIA, new genus 



Body somewhat depressed, the metasome wider than the urosome ; 

 head fused with the first segment and shorter than the rest of the 

 metasome; urosome 4-segmented in female, 5-segmented in male; 

 genital segment undivided; caudal rami lamellar, elongate. First 

 antennae 8-segmented, the segments saucer-shaped and more or less 

 telescoped in the female, enlarged and angular in the male; exopod 

 of second antenna 1-segmented. Segments of first exopod fused into 

 one, endopod 2-segmented, both rami prehensile ; exopods of second, 

 third, and fourth legs 3-segmented, endopods 1-segmented, with a 

 single apical seta; fifth legs 2-segmented, basal expansion rudimen- 

 tary and unarmed. A single ovisac. One species found here. 



Genotype. — Emertonia gracilis., new species. 



EMERTONIA GRACILIS, new species 



Plate 11 



Occmrrence. — Both sexes in considerable abundance were washed 

 from the sand of Buzzards Bay bathing beach at Woods Hole (male 

 holotype, U.S.N.M. No. 63430) ; it was also obtained in smaller 

 numbers in the sand at Nobska bathing beach and on the shore of 

 Cape Cod Bay at Dennis bathing beach. 



Color. — Body transparent and colorless, without any markings; 

 eye invisible. 



FcTnale. — ^Body somewhat depressed and tapered backward; free 

 thoracic segments short and all about the same length, the second 

 and third segments as wide as the cephalic segment, the fourth and 



