300 



THE AMERICAN 



that each succesaive pair of legs is more and more marl<ed 

 with black. In Ephemeridcc, on the contrary, the front pair 

 of legs is normally by far the darkest, the four hind legs 

 being nearly alike in their coloration. And so with other 



Ilia; the 

 iicnlKte, 

 except 



live. Neither do those who still cling to this alrao-st ex 

 loded doctrine make the least attempt to solve this insolubl 

 li'-mi. li^it i'l thr words of I\Ir. Wallace, are content t 



Mli'A il ' ■, :,hii.s vVins hoiiry-yellow. Length 'J 



111 , iiiM.i h .inj ^ c.npluivd ;it large; f^ unknown. By 

 far the hirgi-.^t spiciis that I have seen, and readily distin- 

 guishable by the 9-jointed antennie, the suture between the 

 Sth and 9th joint being as distinctly a free suture as any of 

 the others . 



GENUS DECATOMA. 

 Si/noplical table, to find the species desnibcd below. 

 ,1.— A di tinct stiRinatic dark band on tlic front wing. 

 a. Body mually black. 



1. Head mostly pale ------ varians , n. sp. 



2. Head entirely black ----- nigricepa, n. sp. 

 6 Body almost entirely pale - - - - nubiliBtigma, n. sp. 



Ji —No stiginntic dark band. 



a. Body mostly black ----- hyalipenms, n. sp. 



b . Body almost entirely pale - - - simplieistigma, n sp. 



aften ii 



venter often more or less piceous or rufous ( 



iiiii' base and 

 Iigmaticpatch 

 vay across the 

 appear 





De^^crilKMl from 2i> (^ "i-j § > that came out irom the Cyni- 

 pidous oak-gall Q. podoijra;, Walsh, of the same year's 

 growth, September 1th— Oct. 11th, aud 6 jf 2 $ that came 

 out from the same gall, only of last year's growth. May 21st 

 — lune 21st. I'rom the Cynipldons oak-gall Q. spongifica, O. 

 S., I have obtained 1 (j" 7 $ , differing in no respect from 

 those produced by the other gall (Q podagra:) , except that 

 they varied in size still more remarkably, the ^ being only 

 07 inch and the largest § as much as 0.16 inch long. From 

 tlie allied oak-gall, Q. inanis, O . S , I bred a single f^ of aver, 

 age size and coloration. A single rather small 2 , bred from 

 the Cynipldons oak-gall, Q. palmlris, O S., growing either 

 on the Black or Laurel Oak, has the occiput black above and 

 the antenna; brown-black above ; but it is otherwise normally 

 colored. 1 possess also 2 c^ 1 5 captured at large, that do 

 not differ flora the normal form. This is an exceedingly 

 variable species, both as regards size and coloration. 



V.ariety dubia, f^ 2 — Thi.s form differs fiom D. varians 

 only :i- l.-l|.-,\^ 1-1. Thr ;iviTMi;\' >i/.<- is mu.'h larger. 



tire abd.jiin-n, bcinK black. 3d, The stigmatic dark band is 

 never bottl2-shaped, but Is of the same width as the stigma 

 throughout. Length (j" 0.13, § 0.16 inch. 



Described from 1 (^ 6 § , bred May 21st — 29th, from the 

 Cynipldons Oak-gall Q. momma, Walsh M.S., of the preceding 

 year's growth. This gtill, it should be observed, grows not 

 only on a different species of Oak (Burr Oak) from those on 

 which the galls produciiig D varians grow (Black, Ued and 

 Laurel Oaks), but also on a species belonging to a distinct 

 •subdivision of the genus. Out of a total of 32 ^ 27 $ of D. 

 mrians, bi'ed from the gall of Q. podagra:, but 3 $ , measuring 



Decc 



I ni: 



iituie at llie lip of the abdcimiual peduncle 



I one autumnal $ the lower part of the abdo- 



Gth The legs are on the average more 



with black, and (he coxa- are ohietly black. 



Described from 3 (J" 2 J, bred Sept. 22nd— 2fth, from the 

 Cynipidous Oak-gall Q. ,/icvs. Fitch, of the same year's 

 growth, and 40 (J 16 $ , bred May Sth— 20th, from the same 

 gall of the preceding year's growth. Tills species presents 

 some remarkable analogies with the variety dubia of the 

 preoedingj and the gall Q. ,/lcus, in which it Is partisitic, 

 grows on White Oak — a species belonging to the same group 

 of Oaks as the Burr Oak, on which the gall that produces 



