2 7 



the third and fourth segments are clearly outlined, the remaining 

 plates being indistinct. The eighth segment is quite large, and is 

 terminated by a short conical ovipositor. This organ (Plate V, 

 Fig. 27) consists of three pieces, and is surrounded near its base by 

 about eight tactile hairs. Near the base of the eighth segment 

 above, is the vasiform orifice, which is sub-circular in outline. The 

 operculum is sub-quadrate, the caudal margin being concave. The 

 lingula protrudes caudad beyond the orifice ; is strap-shaped, nar- 

 rowing toward its base, and is minutely setose. The ovipositor is 

 usually bent upward when not in use, and sometimes appears to be 

 held in a vertical position by a projecting fold of the eighth seg- 

 meut. A pair of minute spines is borne on the under side of the 

 second abdominal segment near its base ; a minute pair is present 

 on the dorsum of the fifth, sixth and seventh segments ; two pairs 

 on the dorsum of the eighth segment, and a few spines on the sides 

 a little anterior to the base of the ovipositor. These minute spines 

 are all, as a rule, indistinguishable in specimens mounted in balsam. 

 The writer has not been able to positively locate the spiracles. 



Male. The male (Plate IV, Fig. 19 ; Plate V, Figs. 25 and 26) 

 differs from the female only in size, and in the form of the genitalia 

 and of the abdomen. The length varies from .9 to 1.1 mm., the 

 average length being about .95 mm. The number of abdominal 

 segments is nine, the vasiform orifice and the genitalia being upon 

 the ninth instead of the eighth segment as in the female. The third 

 to sixth ventral plates of the abdomen, inclusive, are quite promi- 

 nent in outline, especially in specimens mounted in balsam. Geni- 

 talia (Plate V, Figs. 25 and 26) forcipate, consisting of two side 

 pieces or claspers and a median penis, the former being provided 

 with tactile hairs. Either the right or left clasper, differing in dif- 

 ferent individuals, appears to have a dorsal swelling near its base, 

 which shows only in a side view. From the side the penis is large 

 at the base, gradually tapering toward the tip. There is a marked 

 upward curve near the base and another less marked upward curve 

 near the tip. From above, the penis appears barrel-shaped at its 

 basal fourth, outwardly becoming flattened laterally ; the outer half 

 or two-thirds is thin, the sides being nearly parallel. The opening 

 at the tip of the penis is circular. It is usually bent upward, and 

 consequently is not seen in its full length from above, but a side 



