368 



THE AMERICAN 



the club not quite as long as the two preceding joints put to- 

 gether, anil when viewed in one direction much wider than 

 they are. Thorax as in Figure 8 (7. Collar very short, trans- 

 verse; parapsiilal grooves obsolete behind. Abdomen when 

 viewed from above, cT oval or sometimes almost obovatc, Q 

 ovate; when viewed in proBle, tf elongate-oval or almost 

 linear, Q triangular with the apex of the triangle downwards. 



[Fig. 7.] 



Semiotpllus rhaleidephagns n sr f (Fig 7 ai —Blue 

 bla k Ik 1 o-l In Head hn ly and c nfl tly i n 

 t 1 1 lilhdAt -Ell fulk 



t n t tl b tl fla 11 m n t 1 1 t d tl 11 



Ilk th th t I T 1 I t 1 I t tf 1 



p 1 uf u th t 1 II II I 1 1 



w th black on tl t 1 I I t 



da k sm ky cl 1 1 k 1 1 1 



f mwh tl t II 1 1 



fth an 1 a 1 1 i t tl h 1 1 



fl n b n uhtltwdthba f 



th w L ngtl S 09—0 11 n h 



The <? (F 7 6) 1 II as f U f on the It the 

 antenna; aie longer, with the flagellai jomts pubescent and 

 distinctly separated, joints 1 and 2 rufous, 3—9 dark brown; 

 2nd, the abdomen is subpetiolate, nan-ower, its tip acute, 

 and with the penis often protruded, the coppery tinge stronger 

 than in Q ; 3rd, the front wing has no dark smoky cloud. 

 Length, (f 0.08—0.10 inch. 



Described Irom 18 c? 15 ? ; namely, 17 cC bred from last 

 year's barley galls June 11th— •22nd, 1 cf sent to me by Mr. 

 Fettit from Grimsby, C. W. , 14 $ bred from last year's bar- 

 ley galls June 14th— 28th, and 1 Q cut out Sept. 10th from 

 barley galls of the same year's growth. 



In but vei-y few other insects, as in this species, does one 

 sex have a distinct dark cloud on the wing and the other sex 

 none at all. But in a European May-fly, Potamanthus mar- 

 ginatiiSf Zetterst., as I was iufoiTOed long ago by Dr. Hagen, 

 the cf has a dark patch on the front wing and the female has 

 perfectly hyaline wings. In Myodites Walshii, Lee— a beetle 

 described from sjiecijnens furnished by myself— the converse 

 I'ule holds good, for here the (^ has perfectly hyaline wings 

 and the has a large dark patch on her wings, as In the 

 Chalcidian now treated of. 



I.arva of the above.— Length 13 inch, from 4J to5 times 

 as long as wide, the body a little tai)ered towards the anus. 

 Color II i):ili.- ghim-uiis ijiecn. the head of a somewll!it daikrr 

 shade, as alsi. i,,ii,ls 



:;^b; 



Two distinct species of Chalcis flies wore found by Harris 

 and Fitch to be parasitic in Joint- worm wheat-galls received 

 from Virginia, and very beiefly described by these authors: 

 1st, a Torr/muSy Q with an ovipositor nearly as long as her 

 body, and 2nd, a Pteromalus (Harris' Inj. Ins., pp. 650-7). 

 This last differs from my species in having the antenna; black 

 with the scape bright copper-color, in the femora being pale 

 yellow, and in the tibia; being blackish, besides other less 

 obvious distinctions. 



SUBFAMILY ENCTRTIDES, Westw. 



Antigaster, new genus —The new genus to which the fol- 

 lowing new species belongs is one of the most anomalous 

 known to science. Many other genera are more or less con- 

 tractile, e. ff. , Agathidium, Clambws, Lciodes and Sphtero- 

 morphus in Coleoptera, and the genera Euryloma and Deca- 

 toma and the different genera of Chrysidida, in Hymenoptei-a. 

 But all these, when they roll up in a more or less complete 

 ball to protect themselves from their foes, roll up downwards 

 with a convex back, whereas Antigaster rolls up upwards 

 with a convex belly and sternum. In the only group of in- 

 sects known to me that approximate to Antigaster in this 

 peculiarity — StaphylinidcE in Coleoptera — the anus is curved 

 up over their backs to adjust their wings under their very 

 short elytra, and never, so far as I have been able to see, for 

 protection against their enemies by the assumption of a con- 

 tractile attitude. It is very true that certain species of these 

 beetles, when approached in a threatening manner, curve 

 the anus over their backs ; but this appears to me to be simply 

 analagous to a similar proceeding on the part of Ltbellulida, 

 which when roughly handled generally curve the anus under 

 the thorax, after the fashion followed by the cf Libellulidce 

 in copulation. In both these cases an attitude which is nor- 

 mally and habitually employed for entirely different purposes, 

 is abnormally and occasionally adopted by way of a threat. 



Antigaster, n. gen.— $ (Fig. 9) Body capable of rolling up 

 the contrary way to a Chrysit. Antenna; as in Figure 9, d, 10- 

 jointed (Sc.-i-S-i-Cl.), springing from near the lower internal 

 corner of the eye, each antenna about twice as distant from 

 the other one at its origin as it is fVom the eye ; basal part of 

 the scape much curved inwards; the flagellmu gr.idually 

 clavate from base to near the tip. No antenual groove. 

 Prothorax but slightly attached to the thorax, very large, 

 distinct, and prolonged upwards in a lateral more or less 

 acute and curved hook, the tip of which is directed forwards. 

 Mesothoracic scutum (Fig. 8, ^, h) foiming along with the 

 hind angle of the pra;scutmu (o) a square excavation adapted 

 to receive the head in repose ; scutum and priescutum closely 

 united together, but connected only by loose membrane 

 laterally with the pleura and behind with the scutellum (c) 

 and postscutellum (d) , so as to be capable of being elevated 

 behind- The scutellum and postscutellum similarly capable 

 of being elevated in front, in which case the mesonotum, 

 when viewed in profile, lies in an angle of 80° ; this is the 

 position of repose. The same parts, when depressed for 

 flight or walking, and viewed in profile, lie in a gentle curve 

 forming a circular arc of only 30", instead of an acute angle. 

 CoUare very short, and only visible when the mcsonotal sub- 

 segments are depressed, its hind edge uniting with the tri- 

 angular priescutnm In a quadrant, the convexity of which is 

 towards the head. Abdomen clavate, its upper surface flat 

 or a little excavated, its lower surface rounded Tarsi all 

 5-jointed, with the basal joint the longest. Front femora 

 and tibiae robust. Middle legs with their cox;e springing 

 from the extreme hind end of the mesostemum, the two coxte 

 close together, the femur much depressed and with its inner 

 eil.ijes perfectly straight, so that the two femora unite in as 

 cl use and smooth a joint as do the elytra of most beetles , thus 

 !i .rrning a broad plate to protect the lower surface of the ab- 

 domen in repose; tibial spur very long; first tarsal joint 

 widely compressed and finely dentate below, and tarsaljoints 

 2—5 mmsually robust. Hind legs with their cox.-e springing 

 from the tip of the metathorax, but wide apart so as to admit 

 the middle legs to pass between them in repose. When all 

 the four hind coxk are directed backwards, the tip of the 

 middle coxa; roaches as far as the middle of the hind coxre. 

 Front wings with the subcostal vein uniting with the costa 

 about half way to the tip of the wing; ramus or stigmal 

 branch springing Irom the costa at an angle of 45", straight, 

 clavate, and fliUy one-sixth as long as the extreme breadth 

 of the wing. Subcostal vein in the hind wing somewhat in- 

 distinct. The cT is unknown. 



In the only other Encyrtides in my collection, namely 1 



