95 

 50. Pandalus (Plesionika) martins, A. M. Bdw. 



Pandalus martins, A. Milne Edwards, Receueil de Figures de Crustaces Nouveaux, pi. 18 (1883) : Wood- 

 Mason, Ann. Mag. Nat. Hist. (6) IX. 1892, p. 369 : Adensamer, Denk. Kais. Akad. Wien, LXV. 1898, p. 624. 



? Plesionika semil&vis, Spence Bate, Challenger Crnstacea Macrura, p. 644, pi. cxiii. fig. 3 (and f P. brevirostris, 

 id. ibid., p. 650). 



Plesionika martia, Canllery, Ann. L'Univ. Lyon, 1896, " Caudan" Crnst., p. 378, pi. xv. figs. 1-6. 



Rostrum from 1- to nearly 2- times the length of the rest of the carapace 

 measured in the middle line ; its basal portion, as far as the end of the anten- 

 nular peduncle, is arched and is armed dorsally only with from 5 to 8 — usually 

 g — teeth, five or six of which form a series that gradually increase in size from 

 behind forwards while the anterior two are usually somewhat isolated ; beyond 

 the antennular peduncle the rostrum is straight, ascendant, and quite smooth 

 dorsally, but ventrally it is very closely finely and evenly serrated, the teeth being 

 a good deal concealed in a short fringe of cilia. All the teeth are fixed. The 

 gastric crest of the rostrum is continued to near the middle of the carapace, 

 which is otherwise quite smooth. 



The posterior border of the 3rd abdominal tergum, though convex, is not 

 acutely produced. The 6th abdominal tergum is as long as the telson, and 

 twice as long as the 5th. The telson, though as long as the endopodite of the 

 tail-fan, is shorter than the exopodite. 



The ocellus is distinct but not independent. 



The antennular peduncle does not reach halfway along the antennal scale, 

 its basal joint is much the longest : the unbroken antennular flagella are very 

 much longer than the combined carapace and rostrum. 



The antennal scale is not very much shorter than the carapace proper, and 

 is narrow and tapering, but with the tip truncated. There is a strong spine 

 on the outer and lower aspect of the 2nd joint of the antennal peduncle. 



The external maxillipeds, which are a little longer and stouter than the 1st 

 pair of thoracic legs, reach a short way beyond the tip of the antennal scale : 

 they have a well-developed exopodite. 



All the legs are slender : the last 3 pairs are very much longer than the 

 first 2 pairs, the fifth pair, which are — especially in the female — the longest of 

 all bein°" nearly twice as long as the 1st pair. The 1st pair have all their joints 

 slender and end in a minute dactylus, at the base of which is a microscopic very 

 short fixed finger : the minute and imperfect chela thus formed is a good deal 

 hidden by scattered seta?. The 2nd pair, which are symmetrical and reach a 

 little beyond the far end of the penultimate joint of the external maxillipeds, have 

 a multiarticulate carpus the end of which bears a whorl of setre, and a minute 

 chela which also carries some tufts of seta?. In the 3rd, 4th, and 5th pairs, the 

 merus, carpus, and propodite are very long and slender, and the dactylus is 

 short ■ the posterior border of the merus is armed with slender distant spines, 



