120 AMPHIPODA NOHMALIA. 



Tills p;enn8 diffei-s from Iphhnedia in the fonn of the maxillipcds, 

 in the distinctly cludatc cluinictor of the lii-st i)aii' of gnathopoda, and 

 in tho hirj>-er relative jjrojxii-tions of the .second. 



From the close approximation of this genus to the preceding, I 

 have cliosen for its name that of tho sou of Iphimetha. 



1. Otu3 carinatus, n. s. (Plate XXIII. fig. 2.) B.if. 



Cephalon produced into a rostnmi. Pereion dorsally cai-inatcd. 

 Third sc>;mcnt of the pleon having an elevation near the doreal 

 centre, and the posterior margin produced into a sharp tooth near 

 the lateral centre ; infero-postcrior angle not much produced. 

 Superior antennte short ; peduncle scarcely reaching heyond the 

 extremity of the rostrum ; tlagellum not longer than the peduncle, 

 five-jointed, first joint as long as the other four. Inferior an- 

 tennae shorter than the superior ; flagellum not longer than the 

 last joint of the peduncle. First paii' of gnathopoda chelate, having 

 the carpus as long as the propodos ; propodos cylindrical, distal 

 extremity produced, pointed, and -uith a tooth exteriorly; dac- 

 tylos tipped vnXh. a long straight unguiculus, furnished at the base 

 with fringed spines. Second pair of gnathopoda subchelate, stouter 

 than the first, having the meros and carpus produced infcriorly ; 

 propodos dilated, palm straight, slightly obHque, pectinate ; dac- 

 tylos slightly cui-ved. Pereiopoda short, stout, and strong ; the 

 propodos slightly arcuate in each ; the meros dilated and distally 

 produced ; the bases in each of the three posterior pairs is pro- 

 duced into two teeth-like processes. Coxa of the second pair of 

 pereiopoda excavated to receive that of the thii-d pair, which is 

 angularly produced posteriorly. Posterior pair of plcopoda shorter 

 than the two preceding pairs ; rami unequal, styliform, clean. 

 Telson ovate. 



Length -Tf^ths of an inch. 



Hah. Shetlands (il/v. BarUe). 



36. ACANTHONOTUS. 



Acauthonotus, Oiren, Append, to Second Voi/tiqc N. IF. P>issai/e, p. xc. 



mife, Hist, of Brit. Crust, p. 177; Cat.' Urif. Crmt.B. M. p. o, 

 1850. 



Edwards, Hist, des Crust, iii. p. 24 

 Yertunuuis, White, Cat. of Crust. B. M. 1847. 



Cephalon produced anteriorly. Pereion having the segments short. 

 Pleon ha\ing the segments long. Antenna-; simple. Oral ap- 

 pendages projecting. Manchbles ^^'ith an appendage. Coxae, except 

 the last two, deep, narrow, pointed. Gnathopoda slender, feeble, 

 subcheliform. Pereiopoda sul)equal ; daetyla imguiculate. Poste- 

 rior pair of pleopoda biramous. Telson single, divided. 



