April, 1920] Notes on the Genus Platycotis 211 



var. Platycotis quadrivitta Say. 



Say, Jl. Acad. Nat. Sci. Phila., vi, p. 300, 1831; Complete Writings, ii, p. 379, 

 Membracis. 



Abundant in March and April. St. Augustine (Johnson), 

 DeLand III-25-18 Col. F. Wooten, Lake City IV-9-93 (Station 

 Collection,) -Gainesville III-25-17, III-18-18, IV-17-18. 



This variety may be distinguished at once from vittaia by 

 its coloration : pale yellowish-green with four sanguineous vittae 

 or lines extending near to the middle, the lateral ones short and 

 oblique. Abundant during the latter part of March and through 

 April on oak (Quercus laurifolia and Q. virginiana) at edge of 

 the "hammocks." Sometimes abundant on oak shade trees in 

 the city. It is gregarious, occurring in large colonies of from 

 fifty to a hundred individuals collected along the branches as 

 shown in Fig. 1. 



Technical Description. — Identical in size and structure with 

 vittata. Differs only in coloration, as follows: Ground color of thorax 

 yellowish-green, four sanguineous vittee extending near to the middle, 

 the lateral ones short and oblique, extending backwards and joining with 

 margin of thorax; lower margin of thorax red; tip of posterior process 

 fuscous. Base and costal region of tegmina marked with lighter green 

 and yellow. 



A horned male adult of this variety collected by E. A. 

 Hartley, at Colorado Lake, near Corvallis, Oregon, has the 

 humeral angles, pronotal horn and the sanguineas vittas con- 

 siderably marked with dark fuscous. 



The life history of the species has never been worked out. 

 The writer's observations tend to show that it is single-brooded. 

 According to Funkhouser (1917, Biology of Menbracidse) , all 

 the species studied by him have five instars. The following 

 description of the last stage nymph, presumably the fifth instar, 

 has been drawn up from a large series that produced typical 

 quadrivittata adults. In this stage they are gregarious. The 

 pronotal developments are very pronounced and the wing pads 

 fully formed. 



The vestigial porrect spike of the nymph is strikingly sug- 

 gestive of the adult Platycotis and together with the two simple, 

 heavy spines and bright red eyes make the identification of the 

 species reasonably sure in the last instar. 



