404 [November 



tical. It is observable that Rogers gives the length of this species as 

 .32_.40 inch, {Proc. Ac. Nat. Sc. Ph!l., Feb. 1856, p. 32) and Harris 

 as " about .30 inch," the accompanying figure being .40 inch long. 

 (^Inj.lns. p. 132.)* Thirdly, Haltlca alternata Illig. (= ^-vtttata Say 

 according to LeConte MS.) is stated by Say to be " found in considera- 

 ble numbers on the common elder (Sambucus) and some other plants," 

 and is described by him as having five vittae on the elytra. Although 

 he notices two variations in the coloration of the head and thorax, he 

 says not a word as to the elytral vittae ever being subobsolete or obso- 

 lete. {Soys Worka, II. p. 227.) I have three specimens in my Cabi- 

 net, captured some years ago, but on what plant I have no record, all 

 of which have the elytral vittae deep black, and very nearly as wide as 

 the yellowish interspaces. As the elder grows abundantly near Rock 

 Island, they may very probably have fed in the larva state upon that 

 plant. In the first few days of August, 1864, I captured on the gall 

 Salicis hraaslcoidcs Walsh, which is peculiar to Salix longifolia, a sub- 

 aquatic willow, six specimens with the elytral vittae distinct and black 

 but i narrower than in my Cabinet specimens, and one with the elytral 

 vittae pale and almost obsolete; and on August 6th, I bred a specimen 

 from that gall with the elytral vittae pale and almost obsolete. On 

 August 9th I captured, mostly on the wing, in a patch of Salix humilis 

 — a dwarf upland willow, which bears a gall, Salicis rhodoides Walsh, 

 constructed on the same principle as ^S*. hrassicoides — twenty specimens 

 of this species, one with the vittae distinct and black but 2 narrower 

 than in my cabinet specimens, seven with the vittae pale and more or 

 less indistinct, and twelve with the vittae more or less entirely obsolete. 

 I have also received from Chicago two specimens with the vittae entirely 



* I have noticed that C. Bigshyana Kby. occurs along with its larva exclusively 

 on willows, and C. casta Rogers, oh a weed, the name of which I do not know. 

 Casta is an Illinois and Kansas species, and is supposed by Dr. LeConte (MS.) 

 to be a mere variety of pulcra Fabr. ; but jtulcra, which is a much larger spe- 

 cies, does not occur near Rock Island, while casta is very abundant there. It 

 would be interesting to know on what plant pulcra feeds, and also on what 

 plant Chr. Philadelphica feeds, which so closely resembles 5('(/.s6ya«a. Of Phila- 

 delphica I have taken but a single specimen near Rock Island in seven years, 

 while Bigsbyana is very abundant there. It will be a great help towards sepa- 

 rating the species of this difficult genus to note the plant or plants on which 

 they are found in company 10 ith their larvae, i. e. on which they feed. 



