158 PROC. ENT. SOC. WASH., VOL. 20, NO. 7, OCT., 1918 



ters are variable and do not always assume the same combinations 

 they cannot be considered of generic importance and as no other 

 characters are known, the following synonymy is necessary: 



Genus Laurentia A. Costa. 



Laurentia, A. Costa, Rendic Accad. Sci. Fis. Napoli, vol. 4 (2), 1890, p. 193. 

 Syn. Astochus. MacGillivray, Can. Ent., vol. 46, 1914, p. 108. 

 Syn. Kincaidia MacGillivray, Can. Ent., vol. 46, 1914, p. 137. 



The North American species belonging to this genus may bo 

 distinguished by the following key: 



1. Entire insect mostly rufoferruginous dilula (Cresson). 



- Head and thorax mostly black 2 



2. Mesepisternum black rubens (Cresson). 



- Mesepisternum with yellow spot 3 



3. Scutellum black edwardsii var. ruficorna (MacGillivray). 



Scutellum yellow or partly so. edwardsii var. edwardsii (Cresson). 



> 

 Laurentia edwardsii var. edwardsii (Cresson) 



Tenthredo edwardsii Cresson, Trans. Amer. Ent. Soc., vol. 8, 1880, p. 24. 



The nine specimens of this species in the Museum Collection 

 came from the following localities: Sierra Nevadas Nevada 

 County, California; Nevada; Easton, Washington; "Washington 

 State;" and one from Kalso, British Columbia. Of these nine 

 specimens, five have the intercosta present and on this character 

 would be placed in Aslochus. On the venation of the hind wings 

 one of these five specimens belongs to Kincaidia, one to Astochiix, 

 while the other three have the intercubitella wanting in one 

 wing but present in the other, with the recurrentellae present in 

 both wings. Four of the specimens have the intercosta wanting and 

 would be placed in Kincaidia. On the venation of the hind wings, 

 two of these four specimens would belong to Kincaidia, one to 

 Astochus, while the other has the intercubitella wanting in both 

 wings with the recurrentella present in both. The series also 

 varies considerably in color markings; no two specimens are 

 marked exactly the same. The amount of yellow on the scu- 

 tellum while somewhat variable, (Cresson says, "Scutellum more 

 or less yellow") may be of varietal importance, and we can 

 recognize, as a variety, the form to which Dr. MacGillivray has 

 given the name ruficorna. The variation in color does not follow 

 the variation in wing-venation. Only five of the specimens listed 

 above belong to this variety. These five specimens come from 

 Nevada; Sierra Nevadas, Nevada Co., Calif. 



