INSECTS OF NEW BRUNSWICK. 19 



area, sub-parallel to the outer series ; one or two of the nervules in this area are briefly 

 forked next to the border. The anal veins cannot be seen. 



The length of the fragment is 40 mm.; the probable length of the wing 42 mm.; its 

 breadth at the middle is 14 mm., reduced at base to 4 mm. 



The most important vein in this wing is the scapular, whose branches occupj^ about 

 half the outer margin ; the externomedian is comparatively unimportant, the interno- 

 median occupying a larger area. The more striking features of the wing besides this are : 

 the origination of the principal scapular branch (from which all the scapular nervules 

 arise) and the externomedian vein from a common stem, having its source in a transverse 

 basal nervule ; and the meagreness of the transverse neui'ation, which in no place shows 

 any sign of reticulation. The point first mentioned finds no parallel among insects excep- 

 ting in the Odonata, where it is almost precisely similar. There, as 1 attempted to show 

 many years ago in treating of the structure of the wings of recent and of fossil Neurop- 

 tera, the transverse vein termed the ai'culus in modern nomenclature should be considered 

 as made up of two veins meeting each other ; for the upper of the two longi- 

 tudinal nervures which always originate from it belongs to the scapular vein, while the 

 lower belongs to the externomedian. Here, these two veins appear, at least, to be amal- 

 gamated at the base, but it is not unpossible, and would indeed seem a jjriorl more prob- 

 able, that they run side by side by side to the arculus, and are merely connate in appear- 

 ance from the preservation of the fossil. However, this may be, it would seem as if we 

 had in this peculiar structure the presence of an arculus as a forerunner at this early day 

 of the specialized type of Odonata ; the main scapular branch arising from the arculus is 

 here, as in all normal modern Odonata, the principal vein of the wing,^ from which most 

 of the subsidiary branches arise ; in these two jjoints this fossil wing is distinctively and 

 decidedly Odonate in character ; but if one looks further, one fails to find expected fea- 

 tures, now, and even in Jurassic time, invariably corellated with those mentioned ; espec- 

 ially is a nodus to be sought in vain ; the marginal vein runs without break to the tip of 

 the wing ; for, although it cannot be followed from want of its perfect preservation, all 

 the neighboring veins can, and the number is similar throughout. So too the fine mesh- 

 work of Odonate wings is not only absent, but what cross neuration exists is confined to a 

 dozen or so straight veins for the whole wing. If, however, we consider this uppermost 

 offshoot from the arculus as the main branch of the scapular, and simply imagine the 

 arculus-structure removed, so as to bring this main branch directly and plainly dependant 

 from the scapular vein, one cannot fail to see how close the entire structure would be to 

 what we find in the Sialina. In the latter group indeed, there is no such separation 

 of apical and basal offshoots to the main scapular branch as here, but all the scapular 

 nervules take their rise, not from the vein itself, but as here from a principal scapular 

 branch, arising far back on the scapular vein ; the general relations of the different 

 areas of the wng are also much the same in both, while the cross venation is very 

 similar. Here as there, the internomedian vein and its branches are of more impor- 

 tance — cover a wider area and bifurcate far more — than either the externomedian 

 vein on the one side, or the anal on the other. We have here, therefore, as I pointed out 



^ It is termed vena principalis in the modern nomenclature not arise in the same way as in otlnr Odonata, but liastrans- 

 of students of Odonata. In some Calopterygidae it does ferred its origin to the scapular (median) itself. 



