330 EEPORT OF COMMISSIONER OF FISH AND FISHERIES. 



longer than broad; abdominal operculum large (nearly covering the 

 whole under surface of the pleon), suboral, simple in the female, but 

 consisting of three distinct segments in the male, one median and very- 

 slender, and two lateral, and furnished within -with a peculiar curved or- 

 gan, terminated behind Avith a much elongated seta ; uropods slender 

 uutramous. 



Munnopsis typica M. Sars. 



Mnnnojjsis txipica M. Sars,, Clir. Vid. Selsk. Forli., ISoO, p. 84, 1861; Christ. 



Fjord. Fauna, p. (TO), pi. vi-vii, figs. 101-138, IS'gS ; Clir. Vid. Selsk. 



Forli.,1868, p. 261,1869. 

 G. O. Sars, Chr. Vid. Selsk. Forli., 1863, p. 206, 1864: Reise ved Kyst. af 



Christ., p. (5), 1866; Christ. Fjord Dybvands-fanna, p. (44), 1869; Chr. 



Vid. Selsk. Forh., 1872, p. 79, 1673; Arch. Math. Nat., B. il, p. 353 



[253], 1877. 

 Whiteaves, Aun. Mag. Nat. Hist., IV, vol. x, p. 347, 1872; Deep-sea 



Dredgiug, Gulf of St. La-wreuce (1872), pp. 6, 15, 1373; Am. Jour. Sci., 



Ill, vol. vii, p. 213^ 1874 ; Further Deep-sea Dredgiug, Gulf of St. 



Lawrence (1873), p. 15, 1874. 

 Buchholz, Zweite Deutsche Nordpolfahrt, Crust., p. 285, 1874. 

 Heller, Deuksch. Acad. Wiss. Wien, B. xxsv, p. (14) 38, 1875. 

 Norman; Proc. Royal Soc, vol. xsv, p. 208, 1876. 

 Miers, Ann. Mag. Nat. Hist., IV, vol. ss, p. 65, 1877. 

 Harger, Proc. U. S. Nat. Mus., 1879, vol. ii, p. 159, 1879. 



Plate II, Fig. 11. 



This species is easily recognized among the known Isopoda of our 

 coast by the form of the body, which suddenly diminishes in diameter 

 behind the fourth thoracic segment, so that the last three thoracic seg- 

 ments, bearing the ciliated, swimming legs, are only about half as broad 

 as the anterior part of the body. 



Anterior division of the body depressed, posterior subcyliudrical ; 

 breadth of body less than half the length. Head small, with the length 

 and breadth about equal, equaling the two anterior thoracic segments 

 in length, but of much less breadth, truncate in front and without a ros- 

 trum, bearing near the posterior dorsal margin two minute conical tuber- 

 cles. The eyes are wanting. The antenuulte in the female, when re- 

 flexed, extend to the third thoracic segment, in the male to the fourth, 

 with the flagellum longer than the peduncle, pectinate or furnished with a 

 longitudinal series of long sette, multiarticulate ; segments in the female, 

 23 to 28 ; in the male, G5 to (jij. The antennse are greatly elongate, about 

 five times as long as the body, very slender; peduncle more than twice the 

 length of the body, the last two peduncular segments beset with numer- 

 ous short spinules, arranged in longitudinal rows; flagellum nearly as 

 long as the peduncle, composed of about 130 segments. The external 

 lamella [1) of the maxillipeds (pi. II, fig. 11 h) is narrowed in front 

 with the external margin convex. 



The four anterior thoracic segments are subequal, short, about five times 

 broader than long; last three segments broader than long, less than 



