AS COMPARED WITH THOSE OF LIVING TYPES. 179 



gradually till it is in close proximity, when it terminates near the tip of the wing by 

 striking the v. scapularis ; this last runs close alongside of the v. mediastina and very nearly 

 parallel to it, striking the v. marginalis at just about the tip of the wing. At about one quarter 

 of the distance from its origin it sends forth a branch downwards and outwards, which 

 having passed a distance about equal to that of the undivided parent stem, forks, the upper 

 branch again forking, the upper branch of this fork again forking, and so on, the upper 

 branches in their course gradually approaching nearer to the main stem, connected to it 

 by a single cross-vein or two, and finally reaching the tip of the wing in close proximity ; 

 the various lower branches are connected together by a few scattered cross-veins, as are 

 those of the rest of the wing. The v. externo-media starting and continuing in close prox- 

 imity to the v. scapularis, diverges from it at about half the distance to the branch of the 

 former ; from here it runs parallel to the branch of the v. scapularis and not far from the 

 middle of its whole course, and just below the divarication of the v. scajmlaris, forks, the 

 upper fork sometimes forking again. The v. Memo-media forks from its very origin, the 

 upper fork turning sharply upwards against the v. externo-media. One examining these 

 veins without great care would consider the former a branch of the latter, were it not that 

 the branching does not occur in the lower wing of Chauliodes until a very little past the 

 origin ; beyond its collision with the v. externo-media the upper branch runs sub-parallel 

 with the lower branch of that vein, and sends out branches from the under side more or 

 less. The under branch, with a slight curve, runs directly to the margin, forking once a 

 little before reaching it. The v. analis forks at its origin, the forks being connected close 

 to the base by a cross-vein ; each of the forks again divaricates, and their proximate forks 

 are connected by a cross-vein. 



Hemekobina. 



This family includes a greater variety of forms than any other, even after we have ex- 

 cluded from it many of the lesser families with which they are erroneously associated (as I 

 believe) by Hagen. To comprise the genera Ascalaphus, Nemoptera, Acanthaclisis, Poly- 

 stoechotes, Chrysopa, Sisyra, and Drepanopteryx in one group and show a uniformity of 

 character in the venation of the wings as great as they exhibit in other features, which 

 shall also distinguish them from the other families, and especially from some of those in- 

 cluded within it by Hagen, is certainly more difficult than the definition of many other of 

 the families, including as it does the more aberrant forms of the sub-order. The lower wing 

 of Polystoechotes is perhaps as fair an example as any of the family. 



The v. marginalis is continuous and regular, except in Drepanopteryx, etc., where it is 

 very much curved abruptly forward next the base. The v. mediastina is straight, and ex- 

 cept where the v. marginalis is swollen, as in Drepanopteryx and Chrysopa, is parallel to the 

 v. marginalis, terminating near the tip of the wing by striking either the v. marginalis (e. g. 

 Chrysopa, Drepanopteryx,) or the v. scapularis (e. g. Acanthaclisis, Polystoechotes, Neurop- 

 tera, Ascalaphus, Sisyra). The v. scapularis runs parallel to the v. mediastina most of the way 

 from the base to the tip, where it terminates, generally just at the tip. It sends down a 

 branch, either quite near the base (Polystoechotes, Drepanopteryx, Sisyra), or at about 

 one third the distance from the base (Ascalaphus, Acanthaclisis, Chrysopa), or even so far 

 as the middle of the wing (Nemoptera), which strikes the border so as to include above it 

 seldom less than half of the wing, and often (especially Polystoechotes) much more. 

 From near the origin of this branch it sends forth another branch parallel to the main 



MEMOIRS HOST. SOC. NAT. HIST. Vol. I. I't. 2. 4G 



