17 



carapace ; another ridge or carina runs transversely from the middle of the arcuate, horizontal 

 part of the cervical carina tovvards the middle of the lower margin of the carapace, running 

 partly just near and behind the posterior portion of the branchiostegal carina. 



Sixth abdominal somite alone carinate, the carina obtuse and reaching neither to the 

 anterior nor to the posterior extremity of the upper margin; the 6"' somite which is 5,8 mm. 

 long and 2,8 mm. wide, is more than twice as long as the ^^^ which is 2,6 mm. long. The 

 telson that is 4,5 mm. long, i. e. three-fourths the 6"> somite, tapers rather strongly and 

 carries at the posterior extremity two small, movable spinules ; it is deeply grooved and, as 

 in Genn. borcalis, there is perhaps a small spinule at the posterior third of the lateral margins ; 

 one observes at either side a sharp carina that runs along the total length of the telson. The 

 telson extends just to the middle of the inner lamella of the caudal fan, the outer lamellae 

 are mutilated. Eye-peduncles slightly compressed ; tubercle on the middle of the inner margin 

 large, conical and acute •, cornea globular, of a pale yellowish red colour, hardly as broad 

 as the distal part of the peduncle ; diameter (i mm.) of the cornea measuring Y12 th^ length 

 of the carapace ; a speek of black pigment on the middle of the outer margin of the peduncle 

 just beyond the level of the conical tubercle. 



Spine on the outer margin of i*' joint of antennular peduncle small, not yet reaching 

 to the end of the corneae. Viewed at from above, the 3''^ joint of the antennular peduncle 

 appears a little less broad, but about twice as long as the 2°'', while both joints together 

 are as long as the i^'. Thickened basal portion of the upper flagellum barely longer than the 

 3'''' joint, regularly tapering and at the distal end curved outward, the outer side of the basal 

 portion appearing concave ; while the basal portions are contiguous, the rest of the flagella 

 are remote from one another. 



Basal joint of outer antennae slightly concave above. The antennal scale, 6,3 mm. long 

 to the end of the blade, is a little more than half as long as the carapace, rostrum included; 

 the greatest width near the base is 1,84 mm., the scale being 3,5-times as long as wide. Both 

 the inner and the outer margin are straight and the scale narrows rather m o d e r a t e 1 y, being 

 still 0,82 mm. wide at the level of the base of the distal spine, where it is still almost 

 half as wide as at the level of the greatest width ; extremity of the blade o b 1 i q u e and 

 obtuse, reaching beyond the tip of the terminal spine farther than this 

 spine is long. 



Mandibular palp reaching almost to the end of the eye-peduncles. Merus of 2"'^ maxillipeds 

 much broadened, 4 mm. long and a little more than half as wide; anterior prominence rounded, 

 very large, measuring one-third the total length of the joint and but little shorter than wide at 

 its base ; exopod reaching a little beyond the merus. 



The e.xternal maxillipeds that bear a podobranch reach to the end of the 2'"' joint 

 of the antennular peduncle and closely resemble those of Aiiialopenaetts elega7is'^m\'i\\. Measured 

 along the straight, outer margin the ischium appears to be 4 mm. long and, being 1,25 mm. 

 wide in the middle, a little more than 3-times as long as wide; the merus, 2,7 mm. long, is 

 just half as wide and measures two-thirds the length of the ischium; the carpus, 2,08 mm. long, 

 nearly half as long as the ischium, seems in a lateral view to thicken slightly distally, being 



17 



SIBOGA-EXPEDITIE XXXI.Xa . 3 



