Boone, Crustacea, Cruise of "Alva," 1931 209 



The first male pleopod, when unrolled and examined from the 

 posterior side, is as shown in fig. D. The outer blade is of the usual 

 shape with the lateral-distal margins setose. The tubular inner 

 portion, when unrolled, has the large outer lobe of the irregular 

 shape figured, with two flap-like processes, well separated, on the 

 outer lateral margin and with the main distal margin bearing five, 

 multiarticulate setae, each joint of the main seta bearing a small 

 seta distally; the auxiliary lobe is small, semitubular, concave 

 on the inner side ; the median lobe is less than half as wide as the 

 outer lobe and shorter, with the distal portion rounded, bent ; the 

 terminal process (p. 2) is slender, shorter than the proximal pro- 

 cess (p. 3), both are distally curved, beak-like formations; the 

 lateral process (p. 4) is short, triangulate, with the outer lateral 

 margin irregular. 



The male second pleopod has the inner blade also specialized, 

 it being semitubular with the posterior surface concave and con- 

 sisting of a small, broad, blunt, conical lobe situated about the 

 proximal third of the lateral margin, and beyond this two longer, 

 slenderer small lobes arising also from the outer lateral margin ; 

 the distal portion of the main lobe is broad, slopingly rounded. 



I have associated the name of Mrs. Consuelo Vanderbilt Smith, 

 a member of the expedition, with this species. 



Genus: THYSANOESSA Brandt 

 Thysanoessa gregaria G. 0. Sars 



Plate 60 



Type : Dr. Sars founded the species on an extensive series of 

 specimens secured by the "Challenger" at seven stations in the 

 South Atlantic, south, also east, of Buenos Ayres, between the 

 Falkland Islands and Patagonia, and other points in the South 

 Atlantic; south of the Cape of Good Hope; off the Australian 

 coast, Sydney to Wellington ; in the North Pacific from Japan to 

 Honolulu; surface. The type series is deposited in the British 

 Museum. 



Distribution: This species has a very wide distribution, 

 ranging in the Pacific as far north as Japan to Honolulu and 

 southward in the Australian waters ; also throughout the North 

 and South Atlantic and in the Mediterranean Sea. 



