314 



to that of the adult, the spines being', however, more numerous and less 

 prominent. The lateral armature is sometimes almost wanting, but oc- 

 casionally occurs to the amount shown in the figure (Fig. 49 d). The 

 dorsal armature is much more scanty, and is either limited to the first 

 and second joints or frequently entirely wanting. 



Fourth stage. — The fourth and last larval stage is shown with char- 

 acteristic armature at Fig. 49 //, /, dorsal and lateral views. Its chief 



difference from the larva of bovis, as 

 already shown in the tabular state- 

 ment, is that the penultimate seg 

 ment ventrally and also dorsally is 

 spinose, as the preceding ones on the 

 posterior margin while in hovis it is 

 distinctly unarmed. The full-grown 

 larva when escaping from the back is 

 of a grayish-white color and ranges in 

 length from 22 to 25 mm. 



PuPARiUM. — Once out of the back 

 the larva rapidly darkens and con- 

 tracts, and the puparium, which is 

 merely the contracted and hardened 

 larva, becomes dark brown, almost 

 black, but otherwise possesses all the 

 superficial characteristics of the larva. 

 Imago. — Length h inch (§ with ovipositor extended) ; general color, 

 black; body more or less densely clothed with yellowish-white, reddish, 

 and brownish-black hairs. The front, sides, and 

 back of the head, the sides of the thorax, a band 

 across the base of the scutellum and the basal 

 segments of the abdomen, are covered with long, 

 yellowish-white almost white, hairs. The head 

 above, central thoracic region, includingprothorax 

 and mesothorax, middle segments of the abdomen 

 above, and legs, clothed with brownish-black 

 hairs, which on the head and thorax are more or 

 less intermixed with whitish hairs. The covering 

 of hairs is shorter and scantier on the head and 

 thorax and the tip of the scutellum and follow- 

 ing parts of the thorax, together with four promi- 

 nent raised lines on the thorax, indicated in the 

 drawing by high light, are smooth and highly 

 polished. The hairs of the terminal segments of 

 the abdomen are reddish-orange, which color also predominates on 

 the hind tibi;^. (See Fig. 50.) 



Fig. 50.— Hypoderma lineata— female, nat 

 ural .size indicated by side lino (original). 



Fig. 51. — Hypoderma line- 

 ata— ovipositor of female: 

 a, from side; b, tip, from be- 

 low-enlarged (original). 



