no. 1591. SCHIZOPODS FROM ALASKA— ORTM. I NN. 



True leys (Plate I, fig. 8) slender, sparsely setose. Propodite 

 three-jointed; dactylopodite short, with a long curved terminal spine. 



Abdomen long and slender. Abdominal appendages greatly dif- 

 ferentiated, but all biramous. First pair of pleopods (Plate I, 

 fig. 9) with outer branch well developed and multiarticulate; inner 

 branch short, about half as long as outer, uniarticulate, with a blunt 

 process near base. Second and third pair (Plate I, fig. 10) with 

 both branches nearly alike and multiarticulate, the inner one hardly 

 longer than the outer, bearing a blunt process at the base. Fourth 

 fair of pleopods (Plate I, fig. 11) with outer branches similar to 

 that of the first, second, and third pair, but inner branch (bearing a 

 blunt process at base) much elongated, about twice as long as outer. 

 This is due chiefly to the lengthening of the three distal joints, of 

 which the first two increase only slightly, while the last one is consid- 

 erably longer than these two together. All three terminal joints are 

 destitute of setae, but the last one bears at its end a long and stout 

 spine. The fifth pair of pleopods is similar to the second and third. 



In young males the pleopods#&re not so strongly developed ; in the 

 second, third, and fifth the inner branch is distinctly longer than the 

 outer (two or three joints projecting beyond the tip of the outer), 

 and the inner branch of the fourth is not so greatly elongated, 

 although the remarkable increase in length of the distal joints is 

 distinctly indicated. 



Uropods (Plate I, fig. 13) well developed, with well developed 

 otolithe ; both branches longer than the telson, but the outer one much 

 longer than the inner. Margins setose, inner margin of the inner 

 branch with a row of seven spines near the otolithe, of which the 

 distal one is remote from the rest. 



Telson (Plate I, fig. 13) elongate-triangular; margins straight, 

 with 16-18 spines along the greater distal part of the margins; the 

 spines increase slowly toward the end, the last one on each side being 

 twice as long as the one preceding it. Between the two long spines 

 forming the outer corners of the telson the apex is truncated and car- 

 ries 4 spines, the two outer ones short and stout, the inner ones very 

 long and setiform. 



The largest female represented in the collection (Station No. 4264) 

 measures 40 mm. The conical process of the antennula? is lacking 

 in the female. The marsupium consists of three pairs of leaflets, 

 of which the first pair is quite small. The pleopods (Plate I, 

 fig. 12) are all uniform, being simple and of the usual shape in the 

 family, increasing slightly in length from the first to the last. 



