PARKER: NEW KNCLAND SARC( >1'II A( ;II)AE. 59 
in leiigtli tt) til)i;i. Middle loxa with a single lou ol" liiistlcs; t't-iinir 
with distinct 'cornl)'; Mihniesotibitil l)ristlt' lacking. Anterior dorso- 
centrals nuicli lonj^er than vestitiire of prescutiiin, nearly as lon^ as 
postsiitiirals; inner presutnrals quite distinct, ahoiit haM" h-n^th of 
outer. Three pairs posterior dorsocentrals (rarely four), all lonj;; 
prescutellar acrostichals present; three ste.rnopleiirals. 
Abdomkn. — Lamellae of fourth ventral plate normally approxi- 
mated alonji; mid-\entral line and hearing' two i)arallel 'brushes.' 
Chactota.v;/.— Second se^'inc^nt without marginal bristles; third with 
two at center, and short, slender ones between these and laterals; 
fourth with a complete row of bristles ending ventrally at forward 
turn of margin. 
Genit.\l segmexts. — Dull orange; first, sometimes wholly or in 
part gray pollinose; its vestiture short and scattered ; outline in profile 
somewhat convex. Forceps prongs slightly convergent at tips. 
Genitali.v. — 'Brushes' of fourth ventral plate extending part way 
toward base of lamellae, the plate without a membranous area at base. 
Posterior plate of penis without roundish or ridge-like protuberances 
on each side; distal extremity broadened and having form of paired 
lateral knobs; median and lateral processes somewhat membranous, 
supported by chitinous structures, former not lobed at end and slightly 
shorter than the latter. 
Described from eight specimens: several others examined. 
Raxge. — Xew England: Mass.: Wellesley, Aut)in-nflale, Mt. Tom, 
Blue Hills, North Abington, Forest Hills, Woods Hole, Wareham; 
Me.: Orr's Island; Conn.: Xew Haven. 
United States: X. Y., Pa. 
The name of this species is meant to draw attention to the * brushes ' 
on the fourth ventral plate. It is at once distinguished from the 
preceding species by the presence of three instead of four postsutural 
dorsocentrals. In this respect it agrees with the genotype, R. hanna- 
todes (Meigen) (Europe and northern Africa). There are three 
instead of five rows of bristles on the anterior face of the posterior 
femur, and the trochanter lacks a 'brush.' This is probal)ly the only 
American species with three dorsocentrals. 
I have two females of this species taken by Dr. H. J. Franklin, at 
Wareham, Mass., larvipositing on excrement. 
(3, 4) Ravinia quadrisetosa (Coquillett) and R. latisetosa form another 
