1903] MORRILL:— TINGITIDS OF THE GENUS CORYTHUCA 129 



trochanters appear to be present though difficult to distinguish. The tibiae are a little 

 longer than the femora and more slender, at the tip bearing several short stout spines. The 

 tarsus consist of two segments, the basal segment being small, not very distinct, and trian- 

 gular in outline viewed from the side; while the last tarsal segment is rounded above, flat 

 below and bears two stout claws at its tip. The two tarsal segments of each leg together 

 are a little more than one half as long as the tibia. A few slender spines occur on the 

 various segments of the legs. 



The abdomen consists of ten segments, only nine of which are ordinarily visible from 

 above. The ninth is quite long and bends downward so that the short anal segment is 

 nearly perpendicular to the surface upon which the insect rests. This segment — the 

 tenth — appears kidney shaped when viewed from the side, with the concave surface where 

 the anal opening is situated directed downward. The second to the ninth segments 

 inclusive, bear on their lateral margins, spines of type no. i which correspond to those 

 described on the sides of the pro- and mesothorax. The dorsum of the second abdominal 

 segment bears two spines which correspond to those on the dorsum of the mesothorax. 

 The fifth and sixth segments are much swollen in the middle of the dorsum and each of them 

 bears three spines on each side, the posterior one being of type no. \ and smaller than the 

 other two which are of type no. 2. On each side of the mid-dorsal line of the eighth 

 segment there arises a spine of type no. 2. Directly behind each of these near the posterior 

 margin of the eighth segment arises a spine of type no. i. Minute pores and spines also 

 occur on the dorsum, the latter being confined mostly to the middle of the sixth segment. 

 A little mesad from each lateral margin, on the ventral surface of the second to eighth 

 segments inclusive, are projections not unlike truncated cones, at the outer, smaller end of 

 which are the tracheal openings. A little mesad to the openings on each side of the body 

 on the venter of each of the fifth, sixth, and seventh segments is a slender spine of type no. 

 3. On each side of the second to eighth segments about opposite the spiracles viewed from 

 above are small areas bounded by chitinous rings. These structures disappear at the first 

 moult and their significance is not known. They appear to be located just below the surface 

 of the body, hence are not represented in the figure. 



Second instar (PI. 3, fig. 5) : Length varying from 1.2 to 1.32 mm.; the greatest width 

 from .68 mm. to .72 mm. The change which occurs at the first moult is not great. The 

 body becomes somewhat broader in proportion to its length. The rostrum reaches to about 

 the caudal margin of the second abdominal segment. The legs are shorter in proportion to 

 the length of the body than before, being a little less than two thirds as long as it. The 

 entire dorsum of the body except for certain definite areas is covered with minute dark col- 

 ored spines. On the venter these spines occur only near the lateral margin. The dorsal 

 spines of the first instar have been changed in two ways : first, new ones have been added, 

 and secondly, spines of type no. i which in the first instar arose from small protuberances 

 (PI. 3, fig. 4) now arise from protuberances which average about the same length as the 

 spines themselves, which are in most cases actually shorter than before. The principal 

 additions of spines in the head region are : a minute one of type no. i added to the pair of 

 the same type which occur just behind the most anterior pair ; two small spines of type no. 

 1 and one small spine of type no. 2 added to each of the next two groups which occur one 

 on each side of the middle line betAveen the eyes. Elsewhere on the dorsum are the follow- 

 ing additions: four minute spines of type no. i now occur on the prothoracic segment, two 

 on each side of the middle line, one being near the anterior margin and the other near the 

 posterior margin of the segment ; on the mesothorax two spines of type no. 2 have been 



