NE *. Mr. Newport on the Anatomy and 
PTERONARCYS CALIFORNICUS d, capite thoraceque saturate brunneis, fronte clypeo labro- 
que rufis, oculis ocellisque nigris, segmentis thoracicis lineá longitudinali interrupta 
flava, abdomine aurantiaco lateribus brunneis, stylis caudalibus basi flavis, antennis 
pedibusque totis atris, alis obscuris nigro-nervosis sed absque maculA stigmali. 
Hab. in Californià, D. Hartweg. 
This species, like others of the genus, possesses the thoracic and abdominal 
branchie. It is very closely allied to P. Proteus, and is of the same size ; 
but it differs from that species in having the antenne, eyes and legs entirely 
black, the labrum and front of the head red, the wings of a darker colour, 
more strongly veined, and without the stigmal patch. The process from the 
eighth segment in the male also, although of the same form as in P. Proteus, 
. readily distinguishes the two species of this sex. It is broad, pilose, and 
deeply scarred in P. Californicus, but is much narrower, and is sparingly 
punctured in P. Proteus. 
I shall now proceed to characterize the new species of Perla, together with 
a species of Nemoura, collected by Mr. Barnston in Canada. 
l. PERLA CITRONELLA (Barnston MSS.), saturatà flava, antennarum articulis 33-35, 
oculis ocellisque brunneis, alis hyalinis pallide luteis margine costali flavis, abdominis 
dorso brunneo.—Long. lin. 3-31. 
Hab. in Canadá, ad Albany River, latit. 54°, 
This species resembles the Perla flava, Pictet, which occurs in Europe as 
far northward as Lapland, but seems to differ from it in the antenne being 
entirely black, the thorax yellow, without a black lateral margin, and in the 
wings being yellow, without green nervures. It is however about the size of 
. Perla flava, and may be only a variety. “ It usually remains on the branches 
or leaves of trees during the day." 
2. PERLA MINIMA (Barnston MSS.), nigra nitida, antennarum articulis circa 26 submo- 
. niliformibus pilosis, fronte paululàm excavato, palpis subclavatis, thorace angusto 
subquadrato, stylis caudalibus 13-articulatis; alis obscuris nigro-nervosis in mari bre- 
vibus obtusis abdomen semicooperientibus in foeeminá amplis corpore longioribus.— 
Long. lin. 13-9, 
Hab. in Canadá, ad Albany River. 
d. Species somewhat resembles the Nemoura nigra, which is from Penn- 
sylvania, . 
