PROC. ENT. SOC. WASH., VOL. 20, XO. 7, OCT., 1918 157 



Measurements. Length, pronotum, cf 4.25 mm.; 9 5 mm.; tegmina, 

 c? 15mm.; width, pronotum, c" 6.5mm., 9 8mm.; metanotum, 9 11 mm.; 

 elytra, c? 6 mm. 



Type, male, Dunedin, Florida, 4-10, 1915. W. S. Blatchley, 

 collector: allotype, female, Auburndale, Florida, no date, N. 

 R. Wood, collector; paratype a, female, same data as allotype. 



Type and allotype in collection of U..S. National Museum; 

 paratype in collection of W. S. Blatchley. 



Catalogue No. 21880 U. S. N. M. 



There is some evidence indicating specific value for the varie- 

 ties of Arenivaga bolliana and apacha erected some years ago by the 

 writer under the names nigricans and infuscata. In addition to 

 the more intensive coloration nigricans is noticeably different 

 from bolliana, as represented by material in the National Museum, 

 it being decidedly less elongate in general dorsal outline. In 

 infuscata the character, in addition to the blackish coloration, 

 pointing to at least incipient specific distinctness, is the spine of 

 the inferior dextr,al plate of the concealed genitalia of the male, 

 which is scarcely more than one half as long as usual in apacha. 



THE NORTH AMERICAN SPECIES OF THE SAWFLY GENUS 



LAURENTIA (HYM.) 



BY S. A. ROHWER, 

 Specialist in Forest Hymenoptera, Bureau of Entomology, Washington, D. C. 



Until recently, when Enslin* treats it as a subgenus of Rhogo- 

 gaster, Costa's genus Laurentia has been considered a synonym 

 of Tenthredopsis. No North American species has ever been as- 

 signed to Costa's genus, but three of the species occurring in the 

 western states described as Tenthredo by Cresson in 1880, belong 

 there. Recently I had the opportunity to study the types of 

 three species described by MacGillivray and assigned to two ne\v 

 genera, namely, Astochns flctcheri, A. alt/r/clii, and Kinca/i/iii 

 nijicorna. Dr. MacGillivray described these three species from 

 as many specimens, and as these specimens show distinct differ- 

 ences it is not surprising that he considered them as distinct. 

 The series of specimens in the collection of the National Museum, 

 however, show that the venational characters chosen by Dr. 

 .MacGillivray to separate the genera Axtnclnix and Kincaidia are 

 subject to either or both individualistic or asymmet rical variation. 

 The differences between Astochus and Kiiicnidia, as pointed out 

 in the original descriptions, is in the presence or absence of the 

 intercosta, recurrentella and intercubitclla. Since these charac- 



* Enslin, Deutsch. Ent. Zcit. Biheft, I'll'-', p. 91. 



