PIIYLLOBRAXCIIIATE CRUSTACEA-MACRUEA. 411 



strong- acute spine. Below the orbit the front margin is produced into u siiort tooth. 

 The posterior margin of the carapace is rather deejjly hollowed dorsally; the siiles 

 are deej). 



The pleon is about twice as long as the carapace ; its second segmeut is not very niucli 

 produced on the sides. 



The telson is long and tapering, with a deep groove along the centre ; its extrcMnitv 

 hears two long spines, with a short one at each side (fig. l). 



The first antennoe (fig. 5) have the basal Joint broad and produced on the outer side 

 into a spine which reaches to the middle of the second joint ; the inner side l)(>ars a sniiiU 

 tubercle near its base; the apex of tin; joint bears a transversB comi) of small spinules 

 l)oth above and below. The second and third joints together barely equal the lirst 

 in length, and the latter bears a very short joint on its outer side, from wliicli sjiriugs tlie 

 short thick flagellum, the inner flagellum b(;ing long and slender. 



The second antenn;e have the peduncle slightly exceeding in length the peduncle of the 

 upper jiair. The scaphocerite is long and rather narrow, and is produced into a spine on 

 its outer margin, -which is subcqual with tiie peduncle in length. The flagellum is lon"'er 

 than the whole body of the animal. 



The mandibles (tig. G) have a cylindrical molar process, a short and much-reduced 

 cutting-tooth (psalistoina), and a 3-jointed palp (synaphipod). 



The first masillas (tig. 7) are two-branched, the larger (outer) branch consistiu"- of an 

 obovate plate fringed with seta-. 



The second maxilla (lig. S) is three-brandied ; tlie inner l)ranch small, verv short, and 

 broad; the second long and plate-like, bilid, and fringed with sette ; the third slender 

 and stiliform ; mastigobninchial plate wide, produced both back and front. 



The first maxilliped (fig. i)) bears a bilobed niastigobrancliial plate, a flat broad basal 

 plate fringed with seta\ a long cylindrical branch, and on the inner side of the latter a 

 smaller more slender branch (ecphysis ?). 



The second maxillipeds (first guathopoda of Spence Bate) (fig. 10) have a short broad 

 plate on the inner face of the coxa, and on its outer a short branchial plume ; the Ijasos 

 carries a long cylindrical branch fringed towards the extremity with setoe ; the ischium 

 and meros are short, broad, and curving round ; the carpos is broader tiian long, and 

 bears a very broad but short propodos fringed with hairs. 



The third maxillipeds are long and pediform ; the basal joint is furnished with a 

 slender single-jointed branch, and there is no trace of branchi;e on the lin\b. 



The first pereiopoda are well developed, and are rough on their outer surface and 

 edges with small spinules ; the long triangular meros aad the short carpos (which latter 

 ends above, or rather on the outer side, in two or three strong tec!th) have deep sockets at 

 their extremities to receive the l)ase of the succeeding joint. 



The second pereiopoda (tig. 11) are hnig and slender ; the basos is very short, the 

 ischium lono- and divided into two unequal joints, the meros still longer, and also divided 

 into two joints, the carpos seven-jointed, and the propodos short, with a minute chelate 

 dactylos. 



The relative value of the joints of this limb is rather difficult to estimate. If we count 



SECOND SJilUES. — ZOOLOGY, VOL. VIII. 6Ji 



