1925] Shoemaker, Amphipoda from Gulf of California 35 



margin with two long, curved, minutely-plumosed setae. One of the distal spines of 

 the third joint of palp is much enlarged, making it appear quite dactyl-like. Second 

 joint of palp with stout seta? on distal half of inner margin. Lower lip without inner 

 lobes, or at best only a mere suggestion of them. Maxilla 1, inner plate with seven 

 plumose setae, below which are several setules, outer plate provided with ten or eleven 

 very stout, curved, toothed spine-teeth, palp with first joint about two-thirds the 

 length of second, second joint evenly rounded distally and provided with many short 

 spines. Maxilla 2 with both plates evenly rounded distally, inner plate furnished with 

 two plumose setae and many long, sharp spines, outer plate furnished distally with 

 many long, sharp, curved spines. Maxillipeds, inner plate reaching to about the 

 middle of the first joint of the palp, armed on truncated end and along inner margin 

 with long, plumose setae, one sharp spine-tooth among the seta? on the truncated end 

 of this plate could be discerned, but if others were present they were completely 

 hidden by the mass of surrounding plumose setae, outer plate reaching beyond the 

 second joint of palp and provided on the inner edge with twelve tooth-like spines, no 

 plumose setae at distal end of this plate, outer edge provided with a row of fine setules. 

 The three joints of the palp all of equal length, dactyl stout with downward-pointing 

 tip. Gnathopod 1 with the terminal spines of second-joint much as in B. catharinensis, 

 front margin with five or six long setae, and two long curved setae near the distal end 

 of hind margin. Gnathopod 2 proportionately longer and more slender than in B. 

 catharinensis, second joint very slender and nearly as long as the third, fourth, fifth 

 and sixth joints combined, fifth joint slender and slightly longer than sixth, sixth 

 joint slender, palm oblique, about two-thirds the length of hind margin and minutely 

 serrate throughout its length, dactyl slightly curved and bearing four forward- 

 pointing teeth and several setules on inner margin. Peraeopod 1, fifth and sixth joints 

 missing, second joint with a row of short, slender spines on front margin and two 

 groups of long bristles near the distal end of hind margin. Peraeopod 2, fifth and sixth 

 joints missing, second, third and fourth joints about as in peraeopod 1. Peraeopod 3, 

 second joint with lobe of hind margin rounding and without any downward dip. 

 Peraeopod 4, second joint not wider above than below, but about the same width 

 throughout, hind margin evenly convex. Peraeopod 5, second joint about as broad as 

 long, lower posterior margin not forming as deep a lobe as in B. catharinensis. Side- 

 plates all much deeper than in B. catharinensis. Side-plate 2 rectangular in outline, 

 front and back margins nearly parallel, lower margin transverse, slightly convex and 

 provided with a row of setules. Side-plate 3 extending slightly beyond the second 

 joint of the peraeopod, sides nearly parallel but slightly wider below, lower margin 

 transverse, very slightly convex and bordered by a row of minute setules. Side- 

 plate 4 with hind margin not so deeply excavated as in B. catharinensis, lower margin 

 bordered by a row of minute setules. Side-plate 5, hind lobe deeper and more acute 

 than in B. catharinensis. Side-plates 6 and 7 differing very slightly from those of B. 

 catharinensis. Posterior lateral margin of abdominal segment 3 bearing a greater 

 number of serrations than that of B. catharinensis. Uropods about as in B. catharinen- 

 sis. Telson proportionately shorter and broader than in B. catharinensis, lobes with 

 apexes acute and inside margins concave, each lobe with two setules near the apex, 

 and each side of telson bearing three setules near the base. 

 Length. — 9 6 mm. 



