REPORT ON THE ANOMURA. 101 



Elasmonotus marginatus, Henderson (PI. XIX. fig. 2). 



Elasmonotus marginatus, Henderson, Ann. and Mag. Nat. Hist., ser. 5, vol. .^cvi. p. 41G, 1885. 



Characters. — The carapace is moderately convex, and covered everywhere with 

 granulations, which are slightly jiubescent and in large specimens show a distinct tendency 

 to become tubercular. The gastric ai-ea is circumscribed, and excavated towards the 

 lateral margins, with two somewhat prominent tubercular elevations on the front margin 

 overhanging the base of the rostrum ; the cardiac area is traversed by a shallow trans- 

 verse groove which separates two lozenge-shaped spaces in front from a similar one 

 behind. The rostrum is broad and flattened, with the apex acute (in the larger specimen 

 it is also acuminate) and bent upwards ; the upper surface is granular and pro\dded with 

 a median carina which occurs also on the lower surface, the lateral margins are finely 

 serrated towards the apex, and hollowed out for the ocular peduncle on either side 

 towards the base. The lateral margin of the carapace bears in front a prominent 

 triangular lobe, and projects considerably between the two divisions of the cervical groove 

 to form a thin lamina, which is distinctly bent upwards ; the posterior margin is raised 

 and 2:rauular. 



The chelipedes are short and stout, with the joints pubescent and spinose. The 

 merus is trigonal, its outer surface is granulated, and the margins are armed with short 

 stout spines ; the carpus is granulated above, and the spines are most numerous on the 

 inner margin ; the propodus is more than twice the length of the carpus, its lateral 

 margins are spinose, and a few scattered granules and spines occur on the upper surface ; 

 the fingers are deeply excavated towards the apices, and the margins of the latter are 

 finely dentate. The ambulatory limbs are robust, with the surfaces of the joints 

 granular, and their margins both pubescent and spinose, the spines being somewhat 

 strongly developed on the anterior margins of the meri, carpi, and propodi ; the dactyli 

 are moderately long, and each terminates in a curved horny claw, while their posterior 

 margins are strongly pubescent, and armed with short horny spines. 



The eyes are immovably fused with the sides of the rostrum ; the peduncle is granulated 

 and prolonged both in front of and behind the rudimentary cornea. The second joint of 

 the antennal peduncle bears a rather prominent external spine ; the flagellum is of 

 moderate length. The merus of the external maxillipedes is granulated externally, and 

 the inner margin is irregularly dentate. 



The abdominal segments are granulated externally, and the second, third, and fourth 

 are transversely bicarinate, the anterior of the two carinas being the more prominent. 

 The penultimate segment has two rather well marked rounded lobes on its posterior 



margm. 



This species bears some resemblance to the preceding, but is easily distinguished by 



(ZOOL. CHALL. ESP. — PART LXIX. — 1888.) Zzz 21 



