1941] 
A New Stizus from Utah 
179 
siderably west of the previously known range of the species. 
Though the head and thorax are normal in coloration, the 
abdomen is remarkable for the extent of the yellow macula- 
tions. Whereas the lateral spots on tergites 3 and 4 are 
usually well separated in texanus, in this specimen they are 
united medially to form broad continuous fasciae, the first 
of which is deeply emarginate anteriorly, but the second 
less so. There is also a broad fascia on tergite 5 which 
covers most of the exposed portion of the sclerite. Even 
the yellow spots on sternites 2, 3, and 4 are exceptionally 
large. 
The following records are of specimens examined by the 
author. 
Arizona: Tucson; “Creosote bush assn.”; August 6, 
1906; G. von Krockow; 1 $ [A.M.N.H.]. 
Texas: 2 $ [M.C.Z.]. Lincecum [collector]; 1 $ 
[M.C.Z.] . Alpine; June 4, 1927 [?] ; 1 $ [U.S.N.M.]. 
Cotulla ; June 21, 1906; H. Caley; 1 > , 4 9 [U.S.N.M.]. 
“Dallas”; Boll; 9^,9$ [M.C.Z. ] and 1 $ [Richard Dow]. 
Laredo; May 16, 1924; 2 $ [U.S.N.M.]. San Antonio: May 
27, 1937; 3 $ [U.S.N.M.]. 
In the following key to the known forms of Stizus occur- 
ring in North America, the author is following the division 
of the Stizini proposed by J. B. Parker in 1929 (Proc. U. S. 
Nat. Mus. 75 (5) : 7-11). According to this classification, 
Stizus unicinctus Say belongs in the genus Stizoides (equiva- 
lent to the tridentatus group of Handlirsch, Berland, and 
Arnold) , and the genus Bembecinus includes the forms with 
a concave propodeum. The name Megastizus is applicable 
to Stizus brevipennis and texanus , but whether these species 
form a group worthy of subgeneric rank is a question the 
author prefers to leave undecided until he has studied more 
material from other regions. 
1. Males , 2. 
Females 5. 
2. Antennae without longitudinal carinae on segments 9 and 
10. Seventh tergite with large ventral lobes 3. 
Antennae with longitudinal carinae on segments 9 and 10. 
Seventh tergite without large ventral lobes 4. 
