134 MISS STAVELEY ON THE NEURATION 



Gorijtes Natalensis (fig. 38 h) (Nyssonh)^) lias 12, and G. mijstaceiis 8, strong sub-basal 



hooks on upper branch of costal nerve, nearer the base than the centre of wing. 

 Mellinus sabulosus (Nyssonid.e) has 7-9 small sub-basal hooks on the membrane of the 



wing, above the costal nerve. 

 Stiziis (Ntssokid^). I have only one specimen, much torn at the base, and an unnamed 

 wing (? Stiztts) (fig. 36) with rather similar veining, which has the appearance 

 of nine partitions in the cell, formed by the divided costal nerve. These may be sub- 

 basal hooks lying down ; but if so, the manner of growth must be peculiar. They 

 are perfectly straight. 

 In the three following species of CKABUONiDiE (which are all that I have seen) they are on 

 the membrane of the wing, above the costal nerve, placed at rather wide intervals, 

 about midway between the base and the distal hooks in 

 Mimesa imicolor, which has 6, and 

 Pemplireclon lugiibrls, which has 4-6 ? 

 Trypoxylon Figtdus has 2, nearer the distal hooks. 

 Dasijpoda hirtijies (fig. 45 «) (Andrenid^) has 2 large and slightly curved hooks on the 



membrane of the wing, above the costal nerve and near the distal hooks. 



In Clmjsis ignita (fig. 25 a) and bidentata (Chbtsidid^), they are large and situated on 



the upper division of the costal nerve. Ignita, 8 ( ? ?) and 7 ( c? ?) ; Bidentata, 8 ? 



The Tentheedinid^ appear generally to be furnished with sub-basal hooks ; but it is 



not always easy in this family to distinguish them from the hairs, or from the distal 



hooks. 



I do not see them in Sylotoma rosce, U. ccernlea, H. cyaneo-crocea, JEL. "A.," or S. "B.," 

 nor in Perga, unless one minute erect marginal hair close to the base of the wing on the 

 otherwise hairless costa is to be called a " sub-basal hook," which I should be inclined to 

 admit, from the fact that Sirex Juvencus has four or five similar hairs — the first nearly in 

 the same situation, and the last quite at the commencement of the distal hooks — resembling 

 the sub-basal hooks in many of the Tenthredinid^. In this Aving, however, there is a 

 scar, not quite marginal, on the costal nerve, between the base and the distal hooks, which 

 may have been the site of a more marked sub-basal hook. In Abia sericea there are about 

 7, as above, but more nearly approaching the character of sub-basal hooks. 



If in the above the sub-basal hooks are difficult to distinguish from the hairs, in some 

 of the following it is as difficult to di-aw a line between them and the distal hooks. In 

 some cases a distinction may be made by the form ; for, as the sub-basal hooks are, in nearly 

 all families, straighter and smaller than the distal, and as the distal in nearly all families 

 are largest and most decided in form towards the base * (diminishing in size, and in some 



* This fact does not always hold good with the Tenthredinidce, the distal hooks of which are sometimes smaller towards 

 the base ; so that the distinction appears inapplicable in this family — the only one I have yet seen which requires it. 

 I put it forward only as a quite arbitrary rule, which may be useful if it is necessary to divide the hooks into two 

 series ; but I believe that in some species there is no real division. 



The hind wings of the Tenthredinidce seem to be, both in the veining and in the arrangement and form of the hooks, 

 entirely irregular. The termination of the veins at the tip of the wing seems to me the most certain character of the 

 group. 



