ENTOMOLOGIST AND BOTANIST. 



369 



species belonging to a genus allied to Cerapterocerus, and 2 

 species belonging to a gemis allied to Coccophagus, the col- 

 larc, though short and transverse, is distinctly visible from 

 above, and the sutures between the mesothoracic prtescutum 

 and scutum, commonly known as the parapsidal grooves, are 

 [Fig. 8.) 



eutii'ely obliterated, as is partially the case in Semlotellus 

 (Fig. 8, C). Figure 8, A, shows the mesonotul subsegmeuts 

 of AitUgasler, as seen from above when depressed for flight or 

 walking. Figure 8, B, shows the corresponding jiarts in the 

 mesonotum of i-'wry/omo, Decatoma and Isosomaj and Figure 

 8, C, those in Semiotellui. In all the three figures tlie coUare 

 (when visible) and the metathorax are shaded to distinguish 

 them from the niesonotum; and in the mesonotum of all of 

 them the pi-escutum is lettered a , the scutum b, the scutellum 

 c, and the poslscutellum d; the coUare (when visible) being 

 lettered e. 



[Fig. i) ] 



Antigaster mirabi 



curling up, c nearly e\irled lip — bo 

 ot>a{lue, (inelv and eluselv pillielati-; hrillnnl 

 pery with pilr|.li< r.llecli./n.s, Mdiilli, hm IimIim. 

 black. Antennae witli the jwiiil.-i rnllh i imli h 

 halt as long as the other joints put I' ,;> lli' ; , j -i 

 portioned as 3, 9, 4, (i, (i, 4, 4, 4, U; llie M-;ip' 

 other joints brown-blaek, those of llie Ihiye 

 Prothornx rufous. Thorax above and on the pie 

 shallowlv riisoso-piiiictate and snhiuili^hed ; I 



(Fi 



brilli: 



ek »iih I. Ill 



111 cli.^el.v 

 ,,|.p, 





idc.r 



111 ureeli relkctiolis, excepl lliul the pleura 

 is, .sonieiinies, ruro-piceous on its disk. Tlie sternum is 

 polished, dc void of sculpture, and black with metallic green 

 relleetinii.-i Meniliranous parts before and on each .side of 

 the seut.l rufous. A bright bine plate in the form of a rect- 

 angular triangle on each sideof themetnllioiiix, the rectangle 

 outwards and forwards. Abdomen black, sulpp.ili^hcd, glab- 

 rous except a few short hairs towards its liji; liiiMiUy slender 

 and regularly widening, with its sides straiglit two-thirds of 

 the way to tho tip, thence regularly curved to the tip, which 

 f .rms au obtuse angle Joint 1 fully } as long as the rest put 

 together, and yellowish semi-transparent white, except its 

 basal \, and exeejit Ihatthebaseof joint 2 shows black through 

 thetr:iiis|i.ireni nverhipof theterminaledgeoljuint I. sheaths 

 of oviposilor Willi.- Legs rufous; hinil r.ix;icUi.-ky, especially 

 above; the f.iui- hind femora and tibia- a liille el.Mided exter- 

 nally with du.sky, and the last tarsal joint in all G legs dusky. 

 F/07!( JI-'iiK/sduAy shading into hyaline on theirterminal l-B: 

 their basal'i and a broad transverse widely inten-upted band 

 A little beyond the middle, both of them whitish subhyalme; 



veins and stigmatic branch brown. Hind Wing* hyaline; 

 veins pale brown. Length c 11 ;i — 0.14 Inch. 



Described from 3 9 taken upon herbage near Rock Island, 

 Ills., in August and September; 2 with the thoracic parts 

 elevated and the body more or less rolled up, the other $ 

 with the thoracic parts depressed and the body extended; (f 

 unknown. Nothing but the almost exact correspondence of 

 all the complicated colorational and structural peculiarities, 

 found in this insect, would ever induce any entomologist, 

 unacquainted with this most remarkable genus, to believe 

 that these three specimens are all identically the same. 



Rock Island, Ills. , March 22, 1869. 



(Fig. 10.) 



[To make this paper as complete as possible, we subjoin a 

 few remarks on the natural history o( Antig otter mirabitia and 

 a description of the <?. In doing so we cannot repress a sigli 

 of regret that so cruel a fatality should have prevented the 

 master hand which penned the Faper from properly com- 

 pleting it. 



During the month of April, 1869, we bred 9 5 5 cT of this 

 parasite from one batch of eggs of Phylloptera ollargifolia, 

 UeGeer, found near St. Louis; and 3 p from another batch 

 received from Louisiana, Mo.— thus indicating that it is by 

 no means of unconmion occurrence in these eggs. As Mr. 

 Walsh's three ? were all captured during August and 

 September, we must infer that this parasite is cither double- 

 brooded, or th*t it (the at least) survives during the sum- 

 mer months from April to Seiitember. The last hypothesis 

 is doubtless the correct one, for if it is double-brooded it 

 must breed in some other kind of eggs than those of P. ob- 

 longifolia, which are not deposited in the latitude of St Louis 

 till the first of September, and which hatch during the fore 

 part of April. 



The larvaof this little anomaly we have never seen, but the 

 pupa (Fig. 10, b) is characteristically flattened and straight- 

 ened so as the better to adapt it to its compressed domicile. 

 The fly, after it is full fledged and well dried, gnaws an ir- 

 regular but usually round hole near one end of the egg, 

 through which to escape to the light of day; the eggs which 

 have been parasitized thus presenting the appearance of 

 Figure 10, a. 



The sexes differ remarkably, and had we not bred both 

 sexes from the same batch of eggs we should scarcely have 

 believed them to be at all allied. The <f (Fig. 10, c) wiU be 

 best described by comparison with the Q . As will be seen 

 by glancing at the figures of the two sexes, he approaches 

 much more nearly than she does to the normal Chalcididous 

 form. We believe it is a very general law in Chalcididx, 

 that where the 5 is gi-eenish the (f is always of a more bril- 

 liant and decided green, and our d Antiyaaler forms no ex- 

 ception, being of a much brighter metallic green than the 5 . 

 We never saw him roll up backwards as does the p, and, 

 from his form, do not believe that he has this peculiar power. 

 He certainly has not that ri-markable and unprecedented 

 power, which she possesses, of setting up or depressing at 

 will themesonotal subsegraenls; and he differs in other re- 

 spects as follows : 



Antigaster mirabilis, H".— Color brilliant metallic-green 

 with faint blue and purple reflections. Head very bright 



