188 S. II. SCUDDER ON THE WINGS OF SOME FOSSIL NEUROPTERA 



recalling vividly the Perlina. The outline of the head is partly very distinct and partly 

 very indistinct, and is docked posteriorly by what indistinctly resembles the posterior two 

 segments of the abdomen of another insect. It is depressed like the other parts of the 

 body, and regularly ovoid in outline. The eyes are rather large, elongate, lateral. The 

 other appendages of the head cannot be made out distinctly enough for any characteriza- 

 tion, the only possible indication of antennas being slight linear depressions in the stone. 

 In those points which can be seen the head closely resembles the Perlina. 



The only portion of the body besides the wings which is preserved with any distinct- 

 ness in the Hemeristina is a fragment of a femur, which from its position on the stone may 

 be assumed to belong to the anterior pair of legs. It is compressed, with a slightly swollen 

 median ridge, as the femora of Pala?opterina are. There is also an apparent fragment of a 

 middle femur and tibia at their union, very indistinctly preserved. The most that can be 

 said about it is that it seems to agree with the same parts in Palaeopterina. 



Now what is most interesting in this connection is. that the Neuroptera have been 

 divided by Erichson, in this being followed by at least the German Entomologists, into two 

 groups, called respectively the Neuroptera (comprising the families Sialina, Hemerobina, 

 Coniopterygidaa, Mantispadae, Rhaphidiidae, Panorpina, and Phryganina), and the Pseudo- 

 neuroptera (which include the Termitina, Embidina, Psocina, Perlina, Ephemerina, and 

 Odonata), founded principally upon one very essential characteristic, — the complete or in- 

 complete metamorphosis, i. e., whether the pupa be inactive or active ; in which latter case 

 the rudimentary wings of the pupa are mere pads protruding horizontally or more or less 

 deflected from the thoracic segments, and in the other are more developed and wing-shaped, 

 encircling the sides and folded over upon the breast like Coleopterous pupae ; and in sup- 

 port of the naturalness of this division it is urged that in no other sub-order of Insects do 

 we find existing simultaneously two so distinct forms of metamorphosis. 1 



We have already seen, by the comparison of the wings alone, that these two families of 

 fossil Neuroptera borrowed from one and another of the other families characteristics of 

 wing-structure, which show their close affinity to them. These families from which they 

 were borrowed, will now be seen to belong, some to one and others to the other of these 

 larger groups, proving that we have in our newly discovered families a Synthetic Neurop- 

 terous Type. And this is still more evident when we carry our comparisons into other 

 parts of the body, as we may in the Palaeopterina, wdiere the meso- and meta-thorax and 

 the abdomen remind us strongly of the Sialina. a Xeuropteron, while the head and eyes, the 

 prothorax and legs, quite as much bring the Perlina, a Pseudo-neuropteron, to our mind. 



In the Hemeristina we have nothing of importance in this direction ; but the femoral 

 fragments agree so closely with the Palaeopterina in its mimicry of Perlina as to lead us 

 to suggest that in its other features it may also have followed somewhat the peculiarities of 

 the Palaeopterina in the equal distribution of its characteristics over a field embracing both 

 the Neuroptera and Pseudo-neuroptera. 



We shall have completed the task we have assumed when we have given in detail the 



1 I cannot, however, discover any one character common to general arc those of the Neuroptera among themselves ; un- 



the wing-structure of one of these two groups which is not less it be that the Phryganina are as widely separated from 



found in the other as well, though the families of Pseudo- the more nearly related families as those of Pseudo-neurop- 



neuroptera arc much more distinct from one another than in tcra are from one another. 



