768 



UN THE ClivETOSOMATlD.E , 



rounded off anteriorly. Here, for a length of about one-fourth 

 the total length of the head, the cuticle is devoid of striie, and 

 is beset with numerous, very long hairs (PI. xliv.-xlv.; Text-fig. 1). 

 Three transverse rows of seta3 are arranged in a semicircle far 

 forward on the dorsal side of the rostrum. The corresponding 

 setse of the three rows are in line, and form portions of longi- 

 tudinal rows; the remaining portions of which are formed of 

 unmodified hairs, extending from the junction of the striated 

 cuticle with the rostrum, to its anterior margin (Text-fig. 1, .o?.s.). 

 A second row, consisting entirely of unmodified hairs, is inserted 

 close beside each of these rows (Text-fig. 1, h.h.). The hairs are 



Figs. 1-2.^ — Ch'i'fosoma falcatnm, n.sp. 

 Fig. 1. — Surface-view of rostrum, showing arrangement of hairs and sets; 



( X 630). 

 Fig. 2. — Longitudinal section through the rostrum in the plane of the 

 lateral sense-organs. The cut ends of the dorsal seta? show above 

 the section; m.t.^ tissue surrounding the mouth; te., mouth-setfe. 

 For other lettering in these and other legends, see postea, under Expla- 

 nation of Plates. 



long and slender, having an average length of 0022 mm., and 

 taper to a fine point. They project vertically up from their 

 point of insertion in the rostrum, but the seta^, which are stout 

 and blunt, and about O'Oiomm. long, are inserted by broad 

 bases in depressions in the cuticle; and are strongl}^ arched 

 forward and downward, bending over the anterior margin of the 



