332 SAMUEL H. SCUDDER ON THE 



The scapular vein throws off an inferior branch before the middle of the wing, generally 

 close to the base, and runs past the extremity of the mediastinal without being affected by 

 it ; it usually reaches nearly the tip of the wing, but in some cases does not extend beyond 

 the middle ; the inferior branch is forked a few times, the branches, verv longitudinal, 

 rarely occupying more than the upper half of the tip of the wing. The externomedian vein 

 is very unimportant, often simple, occasionally divided at the base into two stems, each of 

 which may fork once or twice, and in one abnormal type assuming an importance equal to 

 the main branch of the scapular vein. The internomedian vein nearly always extends so 

 far as to occupy with its branches the whole of the lower margin; the main vein is some- 

 times strongly sinuous, and the branches are nearly always more oblique than in the 

 Homothetidae, more numerous and arising somewhat continuously from the base out- 

 ward. The anal vein is provided with many closely crowded, generally longitudinal 

 branches, the area never reaching beyond the middle of the wing. 



This account of the structure of the wing differs from that formerly given by me (Mem. 

 Bost. Soc. Nat. Hist., i, 189) in some slight particulars only, due to the discovery of addi- 

 tional types. 



The group differs conspicuously from the Homothetidae in the termination of the medias- 

 tinal vein, which impinges upon the scapular vein and not upon the margin of the wing. 

 The relative importance of the externomedian and internomedian areas is reversed, and 

 the contrast between the course of the branches in the two areas generally more marked 

 here than in the Homothetidae. The importance of the internomedian area prevents the 

 anal from encroaching beyond the middle of the wing. It differs from the Xenoneuridae 

 principally in the structure of the lower part of the wing, in the complete independence of 

 the externomedian vein, and in the conspicuous branching of the internomedian. The ter- 

 mination of the mediastinal vein separates it from the Hemeristina, as does the less im- 

 portance of the scapular and externomedian areas. Apart from the termination of the 

 mediastinal vein, the relation of the neuration to existing neuropterous families is much the 

 same as in the Homothetidae. In this respect, however, it more closely resembles the 

 Sialina and Perlina. From these it is separated by the decided deficiency of the scapular 

 branch, whose offshoots rarely fall below the middle of the apex of the wing; by the unim- 

 portance also of the externomedian vein, which is usually simple; by the far greater 

 extent and importance of the internomedian area, which may be considered the remarkable 

 part of its structure, reaching out far toward the tip of the wing, and with the anal area 

 occuping nearly half of the wing. 



Gerstaecker has in various places claimed that their neuration would place the Palaeo- 

 pterina in the Perlina, but nowhere specifies the reasons for this belief. The more perfect 

 presentation of the family characteristics, which we are now able to give, shows that his 

 claim is unfounded ; indeed, the single point in which a special resemblance can be traced 

 is in the distal union of the mediastinal and scapular veins, by the impinging of the former 

 on the latter in the apical half of the wing; a feature which these two families share in 

 common with the Embidina, Raphidiidae, etc. The externomedian vein, for example is 

 either simple or divided almost at the base in the Palaeopterina, while in the Perlina it runs 

 undivided past the middle of the wing, separating two great fields, the one above devoid of 

 cross veins, the one below cut, at least in one sex. by numerous prominent cross veins. 



