222 SCUDDER ON THE CARBONIFEROUS 



These differences, many of which separate also most of the families of Orthoptera from 

 those of Neuroptera, prove that the fossil is widely distinct from Gryllacris, which, on its 

 side, lias a nenration more nearly allied to that of Nenroptera than, perhaps, any other 

 group of Orthoptera ; any comparison with other Orthoptera would therefore be still 

 more vain, the neuration of the fossil wing bearing so much closer resemblance to that of 

 those groups to which Audouin at first referred it- 

 Compared even with Brodia, it will be seen that the essential features of the neuration 

 are the same, with the single exception of the mediastinal vein, which in Brodia ends 

 on the margin not far from the middle of the wing ; while in this ancient " Corydalis " it 

 extends no doubt nearly or quite to the tip. But exactly such a difference as this is found 

 to-day between Raphidiidae and Sialidae, and there can be little doubt that all four of the 

 wings which have now been discussed (comprising all the important fragments of wings 

 from the English carboniferous rocks but one — a cockroach) belong to an ancient type 

 of planipennian Neuroptera. 



Of these, the two which are most nearly related to each other are, unquestionably, the 

 Corydalis Brongniarti of Man tell and the Lithomantis carbonariusofWoodwBxd. Indeed, 

 the resemblance between them is so close that one would almost consider them as belong- 

 ing to the same genus. The basal narrowness of the margino-mediastinal interspace, 

 however, as well as the considerably greater importance of the internomedian area in 

 Lithomantis, forbid this, though the course and general disposition of every principal vein 

 is nearly identical. 



Corydalis Brongniarti, then, being generically distinct from its synchronous allies, and 

 widely different from living types, merits a distinctive name, and may be termed Lithosi- 

 alis, to recall its relationship to the forms to which Audouin first compared it. From 

 Lithomantis it differs in the points just mentioned ; from Brodia in the basal breadth of 

 the margino-mediastinal interspace, the much more numerous branching of the lower 

 veins, and the greater extent of the mediastinal, besides the more uniform breadth of the 

 whole wing ; from Archieoptilus. in the proportionally narrow area occupied at the base of 

 the wing by the upper two interspaces, and the far later division of the externomedian 

 vein. 



Objection would perhaps be made by some to the retention of Woodward's name of 

 Lithomantis for an insect whose supposed resemblance to the Mantidoe is found to be 

 erroneous, and which does not even fall within the suborder to which the Mantidaa belong ; 

 but, aside from the fact that it belonged to an age when the characteristic features of 

 Orthoptera and Neuroptera were more or less blended, its outward aspect is at first glance 

 by no means very different from the insect to which 'Wooilward has compared it ; and the 

 retention of the name has an historic interest which should not lie disregarded ; the num- 

 ber of paleozoic insects is not, and is not likely to become, so great, as to render the name 

 itself an obstacle to a knowledge and easy recollection of its true affinities. 



Attention may here be drawn to the apparent fact (there are many described fossils which 

 1 have not yet studied with sufficient attention to speak in any stronger terms) that while 

 all the carboniferous Neuroptera of Great Britain belong to a single group, not only is 

 this group not represented (at least at all conspicuously) in any other locality, whether in 

 Europe or America ; but also the prevailing forms of other coal measures, the Dictyoneurae 



