192 BULLETIN 15 8, UNITED STATES NATIONAL MUSEUM 



one very long and slender, the two inner ones broad and spinelike; 

 distal segment oblong-oval and densely hirsute, with five setae. Total 

 length, 1.25-1.5 mm. 



Male. — Smaller than the female, with the urosome 5-segmented; 

 anal segment as long as the one preceding it and cleft nearly to its 

 base ; caudal rami a little longer than wide, with a dentiform process 

 at the outer corner as in the female ; terminal setae relatively longer. 

 First antennae 6-segmented, third segment no longer than basal seg- 

 ment and as wide as long, fifth segment longer and wider than the 

 third, end segment very short, strongly curved and swollen at its tip. 

 The end segment of the second antenna has five slender geniculate 

 setae and one long, stout spine at the apex, two spines on the inner 

 and one on the outer margin, and a row of slender spinules across the 

 dorsal surface ; the spines are fringed with short cilia on their outer 

 margins. The exopod is 2-segmonted, the segments nearly at right 

 angles to each other, the basal one with two setae, the terminal one 

 with three setae and a minute spine. The hand of the maxilliped 

 chela is twice as long as wide and is hollowed on its inner surface 

 at the distal end, the margins of the hollow fringed with small spines. 



The first legs are more slender than in the female, but otherwise 

 of the same pattern, including a conspicuous break on the inner mar- 

 gin of the basal exopod segment near the distal end. The other 

 swimming legs are like those of the female; the fifth legs have an 

 elongate, distal segment, with five apical setae, the second inner one 

 longer and more slender than the others ; the outer margin is armed 

 with scattered spines, the inner with a fringe of short hairs; the 

 basal segment is armed outwardly with a seta and two short spines, 

 and has no inner expansion. Total length, 0.75 mm. 



Remarks. — The length of this male indicates that it was probably 

 not fully grown, but even then it is much too large for other species 

 of the genus. The details of the description here given will supple- 

 ment the somewhat meager account given by Brady. The species 

 has never before been reported from our American shores. 



Family PELTIDIIDAE 



Genus ALTEUTHA Baird, 1845 



Body oval or elliptical in outline, the lateral margins of the head 

 turned ventrally; metasome segments with lateral epimeral plates; 

 urosome very short and broad and usually turned downward ; genital 

 segment subdivided, its halves and the abdominal segments also 

 with epimeral plates; caudal rami short and broadly lamellar, each 

 with a stout spine on the ventral surface in addition to the usual 

 setae. First antennae 8 or y segmented, prehensile in the male. 



