627 



of a distinct family. The geiins Nemertes of White is identical with the 

 pi'esent one. It does not at present include more than a single species, to be 

 described below. 



Chelura terebrans, Pliili])pi. 



Clielura terebrans, Philippi, Arch. f. Naturgeschicbte Vol. V, p. 120, PI. Ill, fig. 3. 



Syu.: Nemertes nesseoides, White. 

 » Chelura pontica, Czerniawsky. 



Body short and stout, with the baclc broadly vaulted and slightly 

 setiferons at the posterior border of the segments. Last segment of metasonie 

 produced dorsally to a conical, posteriorly curving ])rojection, ninch longer 

 in male than in female. Urosome depressed, quadrangular in shape, being in 

 female aboiat V» as long as the remaining part of the body, in male nearly 

 half as long. Cephalon about the length of the first two segments of meso- 

 some combined, front evenly deflexed, without forming any trace of a projec- 

 tion, lateral lobes evenly rounded, postantennal corners well defined. Coxal 

 plates successively somewhat dimini.shing in depth; 1st pair rounded quadran- 

 gular in form ; 4th pair nearly twice as broad as they are deep, the 2 

 succeeding pairs bilobate, with the posterior lobe rather projecting and seti- 

 ferons. Epimeral plates of metasome very short, and angular at the lateral 

 corners. Ej'es placed close to the lateral lobes of the cephalon, rather large, 

 rounded, with dark pigment. Superior antennae scarcely exceeding in length 

 Vs of the body, joints of the peduncle successively diminishing in size, fiagel- 

 lum about the length of the last 2 peditncular joints combined, and composed 

 of 6 articulations rather densely clothed with slender bristles, accessory 

 appendage small, biarticulate. Inferior antennae much longer and more strongly 

 built than the superior ones, being generally strongly curved, the outer 3 

 joints of the peduncle nearly fqual-sized, flagellum consisting of a large 

 spatulate joint, densely setiferous on both edges and tipped with one or two 

 rudimentary aiticulations. Anterior gnathopoda with the propodos consider 

 ably longer than the carpus, and slightly curved, being fringed on the upper 

 edge with several ciliated setse, chela rather small, with the thumb broader 

 than the dactylus. Posterior gnathopoda more slender and elongated, with 

 the propodos scarcely longer than the carpus, chela extremely minute. An- 

 terior pairs of pereiopoda with the basal joint somewhat expanded ; the 3 

 posterior pairs with the basal joint scarcely broader than that of the anterior 

 pairs, but fringed posteriorly with a number of strong ciliated setae, meral 

 joint rather expanded and likewise edged posteriorly with strong, ciliated 



