June, 1898.] Dvar : New Species and Larwe of Sawflies. 133 



in a longitudinal plane. Segments scarcely annulate. Thoracic feet 

 large, abdominal on joints 6-12, 13. 



Stage III. — Waxy white, shining, eye black ; width .6 mm. Body 

 pale green, principally from the food. Furcate spines moderate, con- 

 colorous whitish. Feet pale. Length, 5.5 mm. 



Stage IV. — The same. Head .8 mm., length, 6 mm. The body be- 

 comes darker green from the food, but the blood is pale green, tinting 

 the subventral area. 



Stage V. — The same ; width of head 1.1 mm. 



Stage VI. — Entirely green, no marks. Furcate spines rather short; 

 seeming remote, none dark ; arrangement as usual in Periclista with 

 but two spines on the spiracular annulet. Head greenish white, eye 

 black; width T.4 mm. Rarely some of the spines are trifid instead of 

 bifid. A variety occurs with a black patch in the clypeus, but it dis- 

 appears in the last stage, leaving the larva immaculate. Segments 

 indistinctly annulate. 



Stage VII. — (Ultimate.) Smooth, all greenish, not shining ; head 

 and thorax emerald tinted ; dorsal vessel green. Enter the earth and 

 form cells. Single brooded, common on the white oak in May, the 

 commonest of the early spring slugs. Van Cortlandt Park, Bronx Bark, 

 Bedford Bark, Belham Manor, N. Y. ; Fort Lee, N. J., Brookhaven , 

 Bellport and Yaphank, Long Island. 



Key to the American Species of Periduta, o . 



1. Yellow with brown thorax ; no black above diltita Cress. 



Prevailing color black 2 



2. BJack of dorsum mixed with brown, abdominal segments very narrowly white 



bordered pu rpuridorsum Dyar. 



Entirely black above , 3 



3. Clypeus somewhat angularly emarginate 4 



Cbpeus more broadly and shallowly emarginate or truncate 5 



4. Slender, legs whiush and amber brown ; vertical groove from lower ocellar basin 



distinct emarginatus Mac G. 



Robust, legs sbadit g to black on femora ; vertical groove from lower ocellar basin 



short albicollis Nort. 



5- Clypeus shallowly emarginate 6 



Clypeus truncate, scarcely at all emarginate 7 



6. Legs heavily shaded with bli-ckish brown ; transverse groove between upper ocelli 



straight, s igluly crossed by the venical groove subtruncata Dyar. 



Legs mostly wh tish below the femora ; transverse groove slightly bent at junction 

 with vertical one, not crossed by it chionanthi Murtf. 



7. Legs pale, femora brownish, abdomen brownish at sides posteriorly ; vertical 



groove short, the lower ocellar basin reaching nearly to the transverse groove. 



media Nort. 



