ONUPHIS NANNOGNATHUS. 273 



The acicula proper are colorless; they are much more slender than the 

 crochets, being comparable in thickness to the dorsal setae; a little above the 

 surface from which they emerge, they become strongly narrowed, the tip being 

 slender, acute, and a little curved. The setae of the dorsal fascia are numerous 

 and conspicuously long and capillary; distally they become reduced to a fine, 

 distally acute, distinctly curved tip; they are scarcely at all limbate, the wings 

 very narrow, short, and usually obscure. (Plate 44, fig. 8). The pectinate setae 

 occur among the capillary setae as usual ; they are delicate, transparent struc- 

 tures, with a long, thread-like stalk, bearing distally a cuneate plate which pro- 

 jects out widely from the axis on one side but remains nearly straight on the 

 other, being thus strongly asymmetrical. The processes of the distal edge are 

 of uniform length. (Plate 43, fig. 11). The crochets are normally two in num- 

 ber, erect, niarrowed below the teeth ; bidentate, the lower tooth larger and trans- 

 verse, the other one much smaller, proximally erect, distally curved outward 

 above the other; fibrillae distinct, extending distad to the base of cervix and a 

 few short ones evident opposite the lower tooth ; the distal ends of the membran- 

 ous guards rise from the lower tooth to an angular tip just above the upper 

 tooth. (Plate 43, fig. 9). On the first parapodium there is a more dorsal group 

 of finely tipped, non-limbate, capillary setae and a ventral group of coarser, 

 composite, distally dentate setae or crochets. In these the joint is moderately 

 distinct. The distal article is short; it is tridentate, the upper tooth short, 

 curved distocephalad, the two lower teeth short, bluntly rounded, the lower- 

 most being shortest; the membranous guard rises but little above the upper 

 tooth. Farther caudad, e.g., upon the sixth parapodia, coarse unjointed setae 

 with a prolonged, flexible, soft, fine tip appear, these a little farther caudad 

 wholly displacing the jointed forms and then themselves disappearing. (Plate 

 44, fig. 2). 



Carrier-plate of maxillae I about equal in length and breadth; widening 

 from anterior end to about middle of length, where each side projects in an 

 obtuse angle, and from there the plate narrows to a caudal angle, at the apex 

 of which it is acutely incised. The usual triangular anterior area on each half 

 is distinguishable as a paler region set off caudoectally by a ridge or fold in the 

 plate. The blades are narrowed suddenly at about the end of the first third 

 and again at the end of the second third, beyond which the distal portion is bent 

 strongly mesad; as a whole slender. The right blade in the type has a short 

 tooth or accessory process on the ectal side at the beginning of the distal third. 

 Maxilla II of the right side has nine acute, in part reflexed, teeth, and one obtuse 



