82 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. XXVII. 



Fig. 77. — Munidion par- 

 va, first lamella of 



MARSUriUM. X 14i. 



Fig. 78. —Munidion 

 parva, leg of 

 sixth pair of 

 adult female. 

 X 20^. 



an extremely hij^h expansion, the anterior end of which i.s twice as 

 high as the other end. 



The male has all the segments of the thorax dis- 

 tinct. The segments of the abdomen are fused 

 into a single piece. There are no indications of 

 the coalesced segments on the lateral margins of 

 the abdomen, these margins being entire. The 

 posterior portion of this segment is narrower than 

 the anterior portion, its apex, however, l)eing 

 widely rounded. Its length is about one and one- 

 half times its greatest breadth. E3'es are present. 

 Only one specimen comes from the Straits of 

 Fuca, taken b}^ the U. S. Fish Commission steamer Alhttroxx at a 

 depth of 152 fathoms. Parasitic on Miinida quadrlspina Benedict. 

 Type.—Q,^\.. No. 29095, U.S.N.M. 

 This species is a very nmch smaller one than the type 

 species of the genus described b}^ Dr. Hansen," being 

 less than half the size of Munidion j^rmc^s. The 

 present species differs from the type species in its much 

 smaller size; in the relatively larger and differently 

 shaped head; in the larger thoracic epimera (pleural 

 plates); in the differently shaped ovarian bosses; in the 

 smaller and differently shaped abdominal epimera, which do not con- 

 ceal the abdominal segments dorsally as in that species; in the differ- 

 ently shaped carina on the basis of all the legs; in the 

 absence of the sinuous lateral margins of the al>domen 

 of the male; and in the broader apex and greater length 

 compared with the width of the abdomen of the male. 



Family DAJID^. 



DAJUS MYSIDIS Krjiyer. 



Dajus mysidis Kr0yer, Voy. en. Scand., Crust., 1849, pi. xxviii, 



fig.l. 

 Bopynis mysidium Packard, Mem. Bost. Soc. Nat. Hist., 1, 1867, 



p. 295, pi. viii, fig. 3. 

 Lepkq^hryxtis mysidis BuciinoLZ, Zweite Deutsche Nordpolfahrt, 



1874, p. 288, pi. XI, fig. 2. 

 Dajus 7)iysidis Lutken, Crustacea of Greenland, 1875, p. 150. — 

 G. 6. Sars, Arch., Math. Nat., II, 1877, p. 354 (254).- 

 Smith in Harger, Proc. U. S. Nat. Museum, II, 1879, p. 

 158.— Harger, Rep. U. S. Fish Comm., 1880, Pt. 6, p. 312.— 

 G. O. Sars, Crustacea of Norway, II, Pts. 11, 12, 1898, p. 223-225, pi. xxviii, 

 fig. 1.— Richardson, Proc. U. S. Nat. Museum, XXIII, 1901, p. 579. 



Locality. — Labrador; Greenland; Kingigtok; Duck Island; Murchi- 

 son Sound; 73° 48' N. lat., 80° 30' W. long. ; 72° 33' N. lat., 71° 30' W. 

 long; 71° 57' N. lat., 73° 66' W. long. ; m^ 33' N. lat., 61° 50' W. long. ; 



«Bull. Mus. Comp. Zool. Harvard College, XXXI, No. 5, Pt. 22, The Isopoda, 

 1897, pp. 115-117, pi. IV, figs. 2-2c; pi. v, figs. \-\d. 



Fig. 79.— Muni- 

 dion PARVA, 

 MALE. X 23. 



