394 



BULLETIN 15 8, UlTITED STATES NATIONAL MUSEUM 



KEY TO THE SPECIES (BOTH SEXES) 



L Terminal segmeut of first antennae with 5 small spines or den- 

 ticles on inner margin at distal end serricornis (p. 242) 



Terminal segment of first antennae covered dorsally at tip with 



transverse rows of comblilie teeth anglica (p. 242) 



MONSTRILLA SERRICORNIS G. O. Sars 



Figure 242 



Monstrilla serricornis Sars, Crustacea of Norway, vol. 8, p. 19, pi. 10, 1921 



Occun^ence. — Taken in surface tow at Stations 20046, 20056, 20058, 

 20061, Grmrhfus^ in the Gulf of Maine in March and April, 1920. 



Distribution. — Coast of Norway (Sars) ; 

 Gulf of Maine (Bigelow). 



Color. — Body transparent anteriorly but 

 tinged with yellow posteriorly. 



Male. — Body short and stout and somewhat 

 club-shaped in lateral view; cephalic segment 

 a little longer than the rest of the metasome, 

 its lateral margins nearly parallel, its ventral 

 surface prominent anteriorly, but without an 

 oral tubule. Urosome 4-segmented; genital 

 segment with a subclavate copulative organ on 

 its ventral surface; caudal rami small and 

 divergent, each with five nearly equal setae. 

 First antennae two-thirds as long as the ce- 

 phalic segment, 5-segmented, the end segment 

 with five small teeth on its inner margin at the 

 tip ; fifth legs lacking. Total length, 1.75 mm. 



Female. — Unknown. 



Remarks. — The four stations of the Gram/pus 

 named above are so widely scattered that they 

 indicate that the species is likely to be found 

 anywhere in the pelagic portion of the present 

 area. It is also evidently very rare and can be 

 regarded only as a straggler from the open 

 ocean. Sars established this species upon two 

 males taken on the coast of Norway, and all the specimens obtained 

 here on the American coast have also been males. 



Figure 242. — Monstrilla 

 serricornis: a, Male, 

 dorsal (after Sars) ; 

 i, male, end segment 

 of first antenna 



MONSTRILLA ANGLICA Lubbock 

 FlQUBE 243 



Nat. Hist., ser, 2, vol. 20, p. 404, pi. 10, 

 Sci., new ser., vol. 30, pt. 4, p. 576, pi. 



Monstrilla anglica Lubbock, Ann. Mag. 

 1857. — Bourne, Quart. Journ. Micr 

 37, 1890. 



Occurrence. — Two males were obtained in a surface tow at Station 

 20056, Grampus, in the Gulf of Maine, March, 1920. 



