PEPORT ON THE COPEPODA. 107 



Goniopsyllus, 1 n. gen. 



Head and first thoracic segment coalescent. Abdomen not much narrower than the 

 cephalothorax, joints of the cephalothorax very much constricted in front, dilated behind, 

 so as to form prominent lateral triangular processes (PL XLII. fig. 10). Anterior antenna 

 six-jointed (fig. 11), posterior (fig. 12) three-jointed, destitute of a secondary branch. 

 Mandibles wanting (?), maxilhe (fig. 13, a) rudimentary ; anterior foot-jaw very small, 

 feebly clawed at the apex (fig. 13,6); posterior (fig. 14) much larger, three-jointed, 

 terminal claw very slender. First four pairs of feet nearly alike (fig. 15) ; two-branched, 

 branches three-jointed ; fifth pair (fig. 16) small, consisting of one branch only. 



Goniopsyllus rostratus, n. sp. (PI. XLII. figs. 9-16). 



Length, l-40th of an inch (0'65 mm.). Seen laterally the body is curved, moderately 

 constricted at the internodes, and tapers evenly but very slightly from the head to the 

 tail ; the rostrum broad, prominent, and triangular ; seen dorsally each cephalothoracic 

 segment is narrowed in front, and has its posterior lateral angles produced, strongly 

 directed outwards and backwards, and terminating in a sharp point. Anterior antennas 

 six -jointed (V), slender, about as long as the first body segment, sparingly setose ; the 

 last joint longer than the three preceding. Posterior antennae three-jointed, bearing a 

 single long seta in place of a secondary branch. Maxilla rudimentary, consisting of a 

 very small limb, which terminates in a single claw ; anterior foot-jaw small, terminating 

 in three small claw T -like setae ; posterior foot-jaw three-jointed, first tw T o joints long, 

 slender, and nearly equal, third rudimentary, apical claw curved and extremely slender. 

 The first four pairs of feet have the inner branches a little longer than the outer ; both 

 branches bearing long setse but no spines ; the fifth pair short, simple, three-jointed, 

 bearing one short and two long terminal setse. Caudal segments very short; terminal 

 setae two or three, very short. 



One specimen only — a male — of this curious species was found. It occurred in a 

 tow-net gathering from Station 318, lat. 42° 32' S., long. 56° 27' W. 



Its nearest allies are probably to be found in the genera Enhydrosoma, Boeck, and 

 Cletodes, Brady { — Lilljeborgia, Claus), but the mouth-organs in these genera are 

 totally different in character. In Goniopsyllus the maxillae and foot-jaws are extremely 

 small, and the mandible appears to be altogether absent ; at any rate I was unable to 

 find it. The peculiar bend of the feet upon their basal joint calls to mind a similar 

 conformation in Peltidium, while the absence of a secondary branch in the posterior 

 antenna, and the rudimentary character of the mouth-organs, show an affinity to the 

 Saphirinidae. 



1 yui/tct, an angle; ■^/v'Kho;, a flea. 



