100 BULLETIN OF THE 



is nearly as large as the anterior, which is the largest of the series, and the 

 branchiae of the penultimate segment are very nearly alike, and not very much 

 smaller than the pair next in front of them. 



I have seen only four specimens, all males, and but one of these is in the 

 " Blake " collection ; this one from Station 328, N. Lat. 34° 28' 25", W. Long. 

 75° 22' 50", 1632 fathoms. The other specimens are from the collections 

 made by the U. S. Fish Commission off Martha's Vineyard : Stations 893 and 

 952, 372 and 388 fathoms. 



Two specimens give the following measurements : — 



Station 893 328 



Sex .... . $ $ 



Length from tip of rostrum to tip of telson . . . 58.0mm. 65.0mm. 



" of carapax along dorsal line . . . .17.8 19.5 



" of rostrum 1.2 1.3 



Height of carapax anteriorly 4.0 4.5 



" " posteriorly 8.5 9.5 



Breadth of carapax 5.6 6.3 



Length of eyestalk and eye 3.5 3.9 



Diameter of eye 1.7 1.9 



Length of antennal scale 9.0 9.2 



Breadth of antennal scale 2.9 1.3 



Length of sixth somite of abdomen 9.0 10.0 



" telson 7.5 8.0 



" inner lamella of uropod ..... 8.0 8.3 



" outer " " .... 110 12.0 



This is the species which I have referred to as " Sergestes sp." in Proc. 

 National Mus., Washington, III. p. 445, 1881. 



Sergestes, sp. indet. 



There are specimens of a third species of Sergestes from Station 328, N. Lat. 

 34° 28' 25", W. Long. 75° 22' 55", 1632 fathoms, and fragments of apparently 

 the same species from Station 325, N. Lat. 33° 35' 20", W. Long. 76°, 647 

 fathoms. These specimens are all in bad condition and want a large part of 

 the appendages, but they are interesting on account of the modification of the 

 branchial formula. The branchiae are all much smaller than in »s". robust us, 

 the posterior pleurobranchia of the twelfth (antepenultimate) somite Lb replaced 

 by a simple lamella like that upon the somite next in front, and the two 

 branchiae of the penultimate somite are very small, as in 8. wrciiem. The" 

 - is apparently even larger than S. robwtus, and much like it iii general 

 appearance, hut tin; rostrum is much smaller and apparently obtuse, and the 

 eyes are very small, scarcely larger than cyestalks. The specimens are all 

 females. 



