August, '16] 



PARKER: SARCOPHAGA ALDRICHI 



439 



Legs.— Dark. Posterior trochanter without "brush" or latter so small as not 

 to be distinguishable as such: femur cylindrical or sub-cylindrical, clothed beneath 

 with medium long, scattered hair; anterior face with three rows of bristles, those of 

 intermediate row shortest and not developed distally; posterior face without ventral 

 row of bristles: tibia straight or slightly cui'ved, a row of scattered, long hairs on 

 distal half of lower posterior face: tarsus equal in length to tibia, fourth segment at 

 least one half fifth. Middle coxa with a single row of bristles: femur clothed beneath 

 on posterior, proximal half with fine, but rather short hair; anterior ventral row of 

 short bristles complete, posterior row represented by "comb" on distal one-third to 

 two-fifths: submesotibial bristle present. Anterior coxa with two rows of bristles; 

 femur usually with two rows, but if three are present, intermediate row consists of 

 very fine, hair-like, scarcely distinguishable bristles. 



Chcetotaxy. — Bristles usually long and slender. Anterior dorsocentrals, as a rule, 

 scarcely shorter than posterior; only presutural pair of acrostichals developed, 

 slender, others rarely present and if so, very hair-like; inner presuturals slender, 

 nearly as long as anterior dorsocentrals: four pairs postsutural dorsocentrals; pre- 

 scutellar acrostichals present: scutellar apicals present: sternopleurals, sometimes 

 both sides with three or two but very commonly two on one side, three on the other: 

 lower sternopleura with a single row of bristles, otherwise with long hair. 



Abdomen. — Somewhat conical or slightly oval; haijy vestiture longer and finer 

 beneath Ventral plates, as a whole, with their sides slightly converging posteriorly, 

 almost parallel; at sides vestiture long on all three, but centrally vestiture of third 

 shortest and erect. 



Chcetotaxy. — Second segment usually without marginal bristles, at most they are 

 hair-like and decumbent; third with two and often with weaker, hair-like bristles 

 between these and laterals; fourth with complete row ending ventrally in long hairs. 



Genital Segments. — Not conspicuous, normally but small part of first showing, 

 often only membranous band joining the segments. First (g. s.j) ground color 

 varies from brownish orange to blackish, grayish pollinose except "humps" which 

 are not differentiated, vestiture about equal in length to that of second, in profile 

 shghtly arched, marginal bristles absent: second (g. s.2 ), rotund, anal area flattened 

 and extending about to upper limit of pos- 

 terior surface; shining black, often faintly 

 grayish pollinose, sometimes with a 

 brownish tinge. Forceps, normally not 

 visible, blackish brown or orange brown; 

 prongs flattened, their inner edges meet- 

 ing ridge-like for more than two thirds 

 theu' length then separated, but tips 

 so bent that edges normally meet just 

 before the extremities of prongs, the 

 latter spreading slightly, vestiture in- 

 creases in length and amount basally; 

 base with upward flap-like extensions. 

 Connecting membrane just anterior to 

 "humps" with a row of long, slender 

 hairs on each side. 



Genitalia. — Heavily chitinized portions of head of penis (p.) black or blackish: 

 anterior claspers (a. c.) broad and flattened: accessory plates (a. p.) brownish orange, 

 hairy, and with an almost linear extension that parallels forceps for a way. Inner 

 edges of lamelliE of fourth ventral plate fringed with hairs, (p. c. = posterior clasper.) 



Fig. 31. Sarcophaga aldrichi, gen- 

 ital segments. 



