344 
Cleft tenth tergite without inward-point- 
ing lobes or hooks at bases of cercl. 
Wings extending well beyond tip of 
abdomen; with membrane and veins pale; 
a well-formed anal lobe on hindwing and 
So Vy Sees 
ea iy PVE Ree xcs re of he 
GIABDOMINAL TERGITES 
Lepek 
Q SUBGENITAL PLATE 
SUPRA-ANAL 
PROCESS 
‘| DORSAL VIEW 
o' ABDOMINAL SEGMENTS 
Fig. 123.—Alloperla banksi. 
with venation typical of dlloperla as now 
recognized in North America. 
Length to tip of wings 9 mm. ; length 
to tip of abdomen 7 mm. 
FEMALE.—Head, thorax, basal abdom- 
inal segments and appendages in general 
similar to those of male but slightly larger 
in size. Important differences are as fol- 
lows: eighth abdominal sternite, fiom 3. 
with median posterior margin somewhat 
produced backwards over ninth sternite 
in the shape of a V. 
Holotype, male—FLAT CREEK, FlataCreek; 
Neato July 3ye1935- 
Allotype, female——Same data as for holo- 
type. 
Paratypes.—NeW YORK.—FLAT CREEK: Same 
data as for holotype, 94, 59. WARNA: June 
24, 1937, D. T. Ries, 19; June 26, 1937, 
Mary Davis & D. T. Ries, 19. Lloyd-Cornell 
Wild Flower Preserve, CAROLINE: Aug. 16, 
1928, T. H. Frison, 12. CANAJOHARIE: July 
12, 1934, 12. Susquehanna River, ONEONTA: 
July 5,.1935, 19. “IvHAcs; June 4, 1936, J. 
W. H. Rehn, 1¢ (A.N.S.). 
ILLtnots.—Rock IsLAND: 1860, B. D. Walsh, 
9 CM .C Zn) 
Nova ScoTiA.—TRvURO: 
Matheson, 44 (C.U.). 
MIcHIGAN. — Boardman River, MAYFIELD: 
Mayw28; 1939, ie H Frison & H. H. Ross, 
Loe 
The record of this new species from Illi- 
nois is most interesting since it is based upon 
two specimens collected by B. D. Walsh at 
June 26, 1913, R. 
Ittrnois NaturAL History SuRVEY BULLETIN 
Vol. 22,°4rt2 
Rock Island, Ill., in 1860. These specimens, 
found in the unidentified material of the 
Museum of Comparative Zoology, represent 
specimens sent to Hagen by Walsh associated 
with other material collected by the latter at 
Rock Island. Walsh’s (1862) description of 
Chloroperla nana cannot refer to this species 
and probably is the same as Isoperla minuta 
(Banks) (see Frison 1935a, p. 282). 
Dr. Nathan Banks kindly donated one of 
the two Walsh specimens of this new species 
to the Illinois Natural History Survey collec- 
tion because of Walsh’s early connection with 
one of the predecessor organizations of the 
present Survey and because the species was 
not represented in the Survey collection by 
Illinois specimens. Failure to find this species 
in the vicinity of Rock Island, Ill., within 
recent years may be due to some change in 
stream conditions where the species formerly 
existed. Many Illinois streams have under- 
gone great changes during the past 80 years, 
and, with our present knowledge of the very 
localized habitats of some aquatic insects 
within the state, it is readily understandable — 
how slight changes in several very small 
streams at the present time would eliminate 
several other species from the state. It “is 
still possible, also, that the species may eventu- 
ally be found in some small stream near Rock 
Island. 
Alloperla nanina Banks 
Alloperla nanina Banks (1911, p. 336). 
Original description, ¢, Oe 
Alloperla nanina Needham & Claassen 
(1925) ape L2G)e Misidentification. 
Alloperla lodgei Frison (1935), 340). 
New synonymy. Misidentification of Needham 
& Claassen suggested. 
Alloperla nanina Frison 
Taxonomic comments. 
In 1935 I called attention to the fact 
that Needham & Claassen (1925)iinae 
interpreted nanina as a species ‘Without 
a dark dorsal stripe’ on the abdomen, 
whereas, information from Banks indi- 
cated “that the type has such a stripe” 
and I reported that this also was the case 
with “a cotypic female received from 
Banks by the Survey in an exchange of 
material.” 
A restudy I made in 1939 of the typic 
series of nanina in the collectionmas the 
Museum of Comparative Zoology has re- 
vealed that Needham & Claassen (1925) 
were wrong in their concept of the spe- 
cies to be associated with the name of 
nanina and, influenced by their redescrip- 
tion, I (19355) had redescribed mnanina 
under the name of lodget. | 
The cotypic series of manina at Cam- 
bridge now consists of two males and two 
females (M.G.Z. No. 11j34ag8 In ad- 
(1935b, p. 341). 
