After the genus 90 there are 22 more genera, and these are spineless, at least in the case of the two chief genera, 93, _Apatura_, and 104, _Nymphalis_. Of the remainder I know neither figures nor descriptions.[180] In the two genera named the larvæ are provided with two or more spine-like tentacles on the head, and the last segment ends in a fork-like process directed backwards. The body is otherwise smooth, and differs also in form from that of the larvæ of the other _Nymphalinæ_, being thickest in the middle, and tapering anteriorly and posteriorly; neither is the form cylindrical, but somewhat flattened and slug-shaped. If therefore we were to arrange these butterflies by the larvæ instead of by the imagines, these two genera and their allies would form a distinct family, and could not remain associated with the 90 other Nymphalideous genera. We have here a case of _incongruence_; the imagines of the genera 1-90 and 91-112 are more closely allied than their larvæ. From still another side there arises a similar disagreement. The larvæ of the genera _Apatura_ and _Nymphalis_ agree very closely in their bodily form and in their forked caudal appendage with the caterpillars of another sub-family of butterflies, the _Satyrinæ_, whilst their imagines differ chiefly from those of the latter sub-family in the absence of an enlargement of certain veins of the fore-wings, an essential character of the _Satyrinæ_. This double disagreement has also been noticed by those systematists who have taken the form of the caterpillar into consideration. Thus, Morris[181] attempted to incorporate the genera _Apatura_ and _Nymphalis_ into the family _Libytheidæ_, placing the latter as transitional from the _Nymphalidæ_ to the _Satyridæ_. But although the imagines of the genera _Apatura_, _Nymphalis_, and _Libythea_ may be most closely related--as I believe they actually are--the larvæ are widely different, being at least as different as are those of _Apatura_ and _Nymphalis_ from the remaining _Nymphalinæ_. Now if we could safely raise _Apatura_ and _Nymphalis_ into a distinct family--an arrangement which in the estimation of Staudinger[182] is correct--and if this were interpolated between the _Satyridæ_ and _Nymphalidæ_, such an arrangement could only be based on the larval structure, and that of the imagines would thus remain unconsidered, since no other common characters can be found for these two genera than those which they possess in common with the other Nymphalideous genera.