AS COMPARED "WITH THOSE OF LIVING TYPES. 175 



we discover that those of the right anterior wing cut across the principal veins on the left 

 side which correspond to those of the right anterior wing, and therefore that the right wing 

 overlaps the left. The position of each of the wings being then satisfactorily made out, it 

 recpiires only patient examination and studied comparisons to determine of every one of 

 the principal veins, or even detached * branches and cross-veins, to which of the four wings 

 it belongs; 2 and being able thus to delineate the remnants of each of the four wines, and 

 making up from one, so far as is proper, the deficiencies of another, and carrying our 

 point somewhat farther into what is partly conjectural, but guided principally by our 

 knowledge of the relations of this insect to the Neuroptera in general, we are able to re- 

 construct, more or less accurately, the complete structure of all the wings of this insect 

 as partially figured in our plate. 



But this is only one step ; it is indeed but the starting-point. We have now merely a 

 basis, but a firm one, upon which to stand in making our most essential inquiry as to the 

 relation of these ancient types to the other members of the sub-order to which we saw at 

 first they were allied. We need to investigate something of their more intimate relation- 

 ship, and to know how much kinship these forms, which flitted through the oozy marshes 

 of the carboniferous forests, had with the living realities of our own day. 



To determine this point we have in the Hemeristia only the wings to guide us (except a 

 fragment of a leg which is here of but little value), and must therefore inquire whether the 

 different families of Neuroptera have anything in the structure of these parts which shall 

 enable us by their aid alone to distinguish them from one another, and to determine of 

 any wing-form presented to our eye, to which of these groups it belongs. If we can do so, 

 we can ask of course, in reference to the fragments in question, whether they belong to any 

 one of the hitherto described family groups, and to which, — or whether they must form an- 

 other akin to them, but belonging to the same sub-order of Neuroptera. Inquiries made 

 with a view to determine this point have convinced me that this is quite possible, and I 

 have therefore embodied the results of my inquiry in the following statement of the distinc- 

 tion in wing-neuration among the families of Neuroptera. 3 



TERinTINA. 



The v. marginalis and mecliastina run parallel to the very tip of the wing and in close con- 

 junction, apparently with no connection between them ; the v. scapularis also runs parallel 

 to the v. mecliastina, though a little more distant from it, and is sometimes connected with 

 it irregularly by many cross-veins, directed from the v. scapularis upwards and outwards ; 

 generally it forks beyond the middle though sometimes close to the base. The v. extcrno-media 



i Detached by the incompleteness of preservation, for there being more true than any other known to me, though I am 



appear to be none independent. not quite sure that the names are fitly chosen, to suit the ho- 



* It was only at the very last moment of examination that I mologies of wings of insects in general. He enumerates sis 



discovered also the remnants of the v. marginalis and medias- under the following names : the first, counting from the up- 



tina separated from the basal portion of the right anterior per border, the vena marginalis; second, vena mecliastina: third, 



wing, but otherwise unbroken, lying entirely removed from vena scapularis ; fourth, vena exlemo-media ; fifth, vena intemo- 



the wing ; and what is rather remarkable, an exactly similar media ; sixth, vena analis. The spaces between the margin and 



fragment of the left anterior wing also entirely detached and the vena marginalis he denominates area extra-marginalis ; 



lying at right angles to it ; at the outer extremities of the first that between the first and second veins, area marginalis ; be- 



we can see faint indications of fragments of a femur and tibia tween the second and third, area scapularis; between the third 



at their union, which correspond pretty well, so far as can be and fourth, area externo-media ; between the fourth and fifth 



determined, with what we find in Miamia. area interno-media ; between the fifth and sixth, area analis • 



3 I have made use here of the terminology employed by and that between the vena analis and the hind-border the area 



Heer, in his memoirs on the fossil insects of CEningen, etc., as externo-analis. 



MBMOIBS DOST. S0C. NAT. HIST. Vol. I. Pt. 2. 45 



