80 



ii)^ auy involuntary migrations from regions subjected to great muscular 

 disturbance. Tliey may also assist in burrowing, though advance or 

 head movements do not appear to be habitual with these larvae, as they, 

 in common with most ectodermic parasites, are not anaerobic (to use a 

 Pasteuriau phrase), but require the presence of atmospheric oxygen for 

 their maintenance. 



As regards the disposition of the spines it is a noticeable fact that they 

 differ markedly as to their arrangement according to the aspect of the 

 parasite examined. Thus, as is plainly shown in Fig. 10 {a and h), the 

 three rows of spines are single on the ventral and double on the dorsal 

 aspect, the point where the double row ceases being plainly shown in 

 a. This peculiarity is also distinctly exhibited in the species illustrated 

 by Fig. 11, plainly indicating the relationship that exists between them. 



The only segments that are distinctly outlined are the first, which 

 represents the cephalic end, containing the oral cavity, armed with two 

 styles, Fig. 10 {aj, and the second, which immediately follows it. As 

 these specimens have shrivelled considerably since the time of extrac- 

 tion, the segmentation is not as plainly visible as it should be. 



The caudal extremity' is also distinctly shown, though the details of 

 the stigmatous organs are not as plainly delineated as desirable, as the 

 stigmata are doubtless hidden within the anal fissure. In this respect 

 they differ from Brauer's (Fig. 11, a, h, c) and Coquerel's (Fig. 11, dj 

 specimens of similar larvie, with which they otherwise appear to be 

 closely related. 



^.' 







fe. 



Fio. 11. — a, Brauer's fiijuie of entire Dermatohia larva, supposed to be closely allied to specimens shown 

 in Fig. 10; h, cephalic extremity; c, caudal extremity of same specimen; rf, Dermatohia larva fig- 

 ured by Coquerel, and closely related to if not identical with preceding, only seen under a lower 

 power and i)erhaps in an earlier period of development. (From figures kindly furnished by the 

 U. S. Entomologist.) 



In addition to the three rows of booklets, a large number of small 

 punctiform and blackish tuberosities are seen dotted in a somewhat 

 concentric manner above the upper row on the two upper segments 

 and the vicinity of the oral point. 



[ 



