46 



C. H. TYLER TOWNSEND. 



age of pupa cases contained the fully formed pupae, the flies having 

 not yet issued. Besides these, larvae of all sizes from many different 

 colonies were collected. No adults, whatever, were to be seen. 



These larvce are much larger than those of S. pecuarmn and S. 

 meridionale, the largest measuring 13 mm. in length, and differ as 

 well in certain points of structure. It is, therefore, thought well to 

 give a description of them. 



Fully grown larva. — General color of alcoholic specimens blackish, 

 more or less mottled with whitish, the posterior extremity whitish, 



especially ventrally. Very elon- 

 gate in form, narrowed on ante- 

 rior half, segments of posterior 

 half gradually widening to anal 

 extremity, which is stout, with 

 the ventral surface strongly 

 bulged. Head (see figs. 1 and 2) 

 nearly quadrangular, a little 

 longer than wide, dark brown or 

 blackish in color, corneous, with 

 two approximated, irregular 

 black dots on each side near lat- 

 eral margin (see fig. 1), and several rows and groups of nearly con- 

 colorous markings on dorsal portion, as shown in fig. 1. Anteimce 

 pale, nearly as long as one-half anterior width of head, 3-jointed, 



first joint very elongate 

 and narrow, not swollen, 

 slightly curved, with a 

 somewhat faint transverse 

 suture on basal two-fifths, 

 cylindrical below suture, 

 beyond suture very slightly 

 and somewhat irregularly 

 narrowing to tip ; second 

 joint narrower than tij) of 

 first, straight and of equal 

 width, except slightly wi- 

 dened at base, a little more 

 than one-third as long as first joint, and with two small, triangular, 

 bud-like processes, one on each side at base, springing from the junc- 

 tion of the two joints and approximated to the second joint ; third joint 



