390 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 21 



dor: Albemarle Island, Hopkins-Stanford Expedition (Rathbun, 1902b, 

 as M. platysoma) ; Hood Island, A returns (Boone) ; Charles Island, 

 A. Wollebaek (Sivertsen) ; Indefatigable and South Seymour Islands, 

 Velero III (Garth). 



Atlantic analogue: None. A species endemic to the Humboldt Cur- 

 rent littoral. 



Diagnosis : Carapace little longer than broad, granules few and tufted 

 with hairs; four long spines on each branchial region, three being in a 

 transverse line. Outer margin of basal antennal article without a lobe. 

 Lateral lobes beveled and polished, not collared. Male first pleopod with 

 keel broadly rounded and imperceptibly separated from bluntly triangular 

 tip. 



Description: Carapace shorter and broader than in Microphrys 

 platysoma; hairy; with the hairs removed the surface seen to be covered 

 with small pits. Tubercles and granules few; an arch of five tubercles 

 across the gastric region ; two tubercles near the outer edge of each bran- 

 chial region ; a row of tubercles above the posterior margin. Some fine 

 granules on the inner areole of the branchial region ; granules also on the 

 protogastric regions, with a row of granules leading forward onto each 

 horn. Typically four spines on each branchial region, three of these 

 forming a transverse row with the conical cardiac region, the outer spine 

 of the row being marginal ; the fourth spine also marginal but lower and 

 further forward than the third. Between the second and third spines 

 sometimes an additional, smaller, secondary spine. The first or innermost 

 spine (that next the cardiac region) sometimes obsolete and represented 

 only by a low, conical swelling. Each spine and tubercle bearing a tuft 

 of long, curled hairs ; a band of similar hairs running along the antero- 

 lateral margins and along each side of the gastric region to the tips of 

 the rostral horns. On the anterolateral wall two much raised, oval discs, 

 one hepatic and one branchial; the side of the postorbital cup also flat- 

 tened. Margin of the basal antennal segment bearing no tooth or lobe 

 behind the slender anterolateral spine. 



Arm with three triangular teeth above. First leg with a long spine 

 on the carpus and another near the distal end of the merus ; second leg 

 with a spine on the carpus only. (Rathbun, 1925, modified) 



Material examined: 30 specimens from 2 stations: Lobos de Afuera 

 Island, Peru, January 17, 1935, shore, station 391-35, 6 males, 8 females 

 (2 ovigerous) ; same locality, February 14, 1938, shore, station 844-38, 

 8 males, 8 females (5 ovigerous). In addition to the above: 14 specimens 

 from 9 Galapagos stations (Garth, 1946, p. 403), plus 1 ovigerous female 



