98 
S. I. Smith — Crustaceans of the Atlantic Coast. 
have one or more less segments than the corresponding outer branch. 
The number of segments in both the inner and outer rami varies 
somewhat, however: in the fully adult male, 28 , 5 mm in length, there 
are fourteen segments in each of the outer rami of the first pair ; 
twelve in the outer and thirteen in the inner of the second and third 
pairs; eleven in the inner and twelve in the outer of the fourth pair; 
and only eight in the inner and twelve in the outer of the fifth pair. 
In a young male, only 13*5 mm long, there appear to be one or two less 
segments in each of the natatory rami of all the pleopods, although 
the rudimentary rami in the first pair, and the lamellar appendage 
of the inner ramus in the succeeding pairs, are well-developed. 
The rudimentary pleopods of the female do not differ essentially 
from same appendages in the allied genera. They resemble more 
closely, however, the pleopods of the females of the species of Mysis 
than of Parerythrops obesa , the setae with which they are armed 
being fewer in number and much longer than in that species. 
Massachusetts Bay!, off Salem, 33 fathoms, sand and mud, August 
4, 1877, — young male and female; also 33 fathoms, soft mud, August 
13, — one young male. Off Bay of Chaleurs, Gulf of St. Lawrence!, 
50 and 70 fathoms, 1873, — adult male and two females, one, le'S 1 "" 1 
long, the other, 14 mm . 
Psetidomma roseum G. 0. Sars. 
Pseudomma roseum G. 0. Sars, Nye Dybvandscrustaceer fra Lofoten, Christiania 
Videnskabs-Selskabs Forhandlinger, 1869, p. 154 (19); Carcinologiske Bidrag til 
Xorges Fauna, Mysider, part i, p. 54, pi. 4, 1870; Undersogelser over Hardan- 
gerfjordens Fauna, Crustacea, Christiania Videnskabs-Selskabs Forhandlinger. 
1871, p. 263 (20); Archiv for Mathematik og Naturvidenskab, Kristiania, ii, p. 
344, 1877. — Metzger, Jahresberieht der Comm, zur wissensch. Untersuchung der 
deutschen Meere fur 1872, 1873, Xordsee. p. 288, 1875. — Whiteaves, Report on 
further deep-sea Dredging Operations in the Gulf of St. Lawrence [in 1873], p. 16. 
[1874?]. 
Near Jeffrey’s Bank!, Gulf of Maine, 105 fathoms, brown mud, 
September, 1873, — one specimen. Gulf of St. Lawrence!, 1873, 28 
miles east-northeast of Cape Gaspe, 110 fathoms; and 25 miles east 
by north of Cape Gaspe, 210 fathoms, — several specimens at each 
locality. West coast of Norway, at the Lofoten Islands!, 200 to 
300 fathoms; and Ilardanger Fiord, 100 fathoms, and between 400 
and 500 fathoms (G. O. Sars). Oft' Mandel, southern Norway, 220 
fathoms (Metzger). 
