ENTOMOLOGIST AND BOTANIST. 



29: 



original intention of the author, and render 

 more complete the "Joint-worm"' article already 

 alluded to. This paper, from its importance, 

 will commend itself to the scientific portion of 

 our subscribers; and the generalization.s con- 

 tained in it will amply repay its perusal by the 

 more general reader. We shall, as far as we 

 are able, complete it, by adding a description of 

 (^ Antigaster mira/ti/ix. Euitou. 



On the (irmiii 



(llf llv 



IE TUKOIIY OF BPECIKS, 

 JTIGASTEH, A NKW AND V 

 IJENUS OF ClliLCIDID.i:. 



FAMILY CHALCID1D«. 



Front Winffs veined on the paltcfn shown in Fifjnrcit 1, -J, :>, 



This very difficult and very extensive family has hitliiii.p 

 bei n almost entirely neglected by the entomologists nl llu- 

 United States. I have materials for the revision of all the 

 different groups found in this country; but to complete such 

 a work would require far more space than is here available . 

 Consequently, I shall in this Pai)er confine myself chiefly to 

 the discussion of one subordinate gi'oup, Eurytomidcs, first 

 defining and limiting such genera of that group as I find in 

 my collection, and secondly describing the species in my 

 possession appertaining to those genera, with such brief 

 notes on their natural history as I am able to furnish. Of the 

 other two Chalcidiau genera that I shall have occasion to 

 refer to, one is well known to N. A Hymenopterists, and the 

 other is a decidedly new and most anomalous and remark- 

 able genus. In the latter case, 1 shall, of course, be com- 

 pelled to publish a new generic name; in the former case, 

 for lack of space to treat the subject as it ought to be treated, 

 I shall simply adopt the est;ibli>li. d nnmcuclature. 



It will be seen at once, iV.nii my ]]iiii- "u the habits of tlie 

 various speCKAoi Eurtjtointdit., wliicli it will be necessary 

 to describe, that many of tlusi- chnlcis flies are parasitic 

 upon several different species, and that occasionally the very 

 same Chalcis fly is parasitic upon species belonging to differ- 

 ent Orders. (E. g. Eurytoma studiosa. Say, and Decatoma 

 nubilistigma, n. sp.) In several cases Eurytomidous forms, 

 that appear to belong to Dm- s;imc sincics, present certain 

 raoreor less constant ditVi 1.11. (.. ulhn ili.y infest difffreiit 

 species of insects. Such f.iini- -i^iu i.. .l..-crve a distinctive 

 name, which I have accordiiiglj K'veii to them, classifying 

 them as mere varieties. Whether they be really varieties, 

 or whether they be distinct species, depends — accoi'ding to 

 my views— upon the difficult and almost insoluble question, 

 whether such so-called varieties attack indiscriminately the 

 different insects upon which the so-called spt-cies to which 

 they are referred is foimd to be parasitic, or whether each of 

 them exclusively attacks the particular insect ujion which it 

 is itself found to be parasitic. In the former easel should 

 classify them as varieties, in the latter case as species ; for I 

 have always considered the promiscuous interbreeding of two 

 forms — whether actually ascertained or analogically inferred 

 —as the true test of specific identity; and if such so-called 

 varieties attack promiscuously the different insects upon 

 which the whole so-called species is parasitic, the inference 

 is that they derive that propensity, by the Laws of Inhe it- 

 ance, from interbreeding habitually with the other form.s 

 comprehended under the so-called species If, on the other 



Fain 



. Fart II, Chaluididui 



v.r.i ii.i.r. hi u iii.-l that a I lyraenopterous parasite 

 1 l.in..|.. ,r/,,;,5., iiiiiita), which is exceedingly vari- 

 illi in size, in coiiiring, and in the structural peculi- 

 if the four terminal teeth of the abdomen— two of 

 eth being in one variety {Mcrope) actually obsolete— 



CI/SIS 



i- |K rliiiiis (liie to till/ v^iruition in .^i/.e ot the larvie upon 

 wliicli it preys.' May not the structural and oolorational 

 \iiTiati.ins, also, be due to similar causes, and may there not 

 1m- .li-fiiic-t varps— or, as I should call them, distinct species— 

 ol ilii- ill-..!, which prey exclusively or almost exclusively 

 lip. ,11 .li-iiii.i uv..up3 of Wasps, and have tran.smitted .inch 



In that case, as'-well as in lli.' li\ i- ili. li. al .■a>i-s just now 

 referred to among the C'/iffl/. : . n il.l liave Ento- 



mophagic Varieties and Eiii.n i , ,, -; , i,., strictly an- 

 alagous to what I have de.Miili. I i- I li.i >"i.lia;;ic Varieties 

 and Phytophagic Species. (I'roc. Ent . Soc. P/u7., III., pp. 

 403-431); v., pp. )94-31(J.) 



The club of the Chaloididous antenna ajipears to be nor- 

 mally cnnilwispd .if al.niit Mini' rnnnnte and often mnre or 

 less conlliii'iil I'.iM- I i.i.M-:... :i..|li..r-. iit . I, ■-.Til. in- (he 



number ..i J i- m !• ' •. ' I'i'. n- am. nn;., ~. . m |., have 



always CI. uiii.-.l ili. i.| i . ■ ..i iIm- rlnl. a.- inn. j.inits. 



This I have never don'..', ibl, because they really are nut true 

 bona fide joints, and, secondly, because in the same species 

 some specimens look as if they had a two-jointed, some as if 

 they had a three-jointed, and some almost as if they had a 

 four-jointed club. But, to prevent confusion, after stating 

 the number ol veri able free joints in the antenna— say, for 

 instance, eight— I have always appended the formula "Scape 

 +G-|-Clnb," or "So.-f-6-t-Cl," 



As to certain very minute joints wliich certain European 

 authors have described as existing in certain genera between ' 

 the pedicel or second joint of the antenna, which is generally 

 short, and the ,^'eiiorally elongate third joint or first joint of 

 the fla.;;. lliiiii; I li.Iie\. tliem not to be true horny joints at 

 all, but mil. wiiiiid.- ..f the connecting membrane. Cer- 

 tainly, in til.. iyi.i...al ant. una, whether in Hymenoptera or in 

 Coleoptera, the third joint is always a more or less elongate 

 joint, and never a very minute one, as is so often the case 

 with the pedicel or second joint + 



SUBFAMILY EURYTOMIDES, Westw. 



Collare very long and transverse-quadrate, as in FiijureS, 

 B, c; hind thighs not swelled. 



Gexus Eurytoma. (Fig. \,a<^,b^ ) Body partially 

 contractile, as in Chrysidida, with a deep, finely-sculptured 

 groove for the reception of the middle femora, reaching I'rom 

 the base of the middle coxa to a point immediately beneath 



vethiouffhout 



