134 MISS STAVELEY ON THE NEURATION 
Gorytes Natalensis (fig. 38 b) (Ntssonid^) lias 12, and G. mystaceus 8, strong sub-basal 
hooks on upper branch of costal nerve, nearer the base than the centre of wing. 
Mellmus sabulosus (Nyssonidje) has 7-9 small sub-basal hooks on the membrane of the 
wing, above the costal nerve. 
Stizus (Nyssonid^e). I have only one specimen, much torn at the base, and an unnamed 
wing (? Stizus) (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 Crabronid J3 (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 unicolor, which has 6, and 
Pemphredon lugubris, which has 4-6 ? 
Trypoxylon Figidus has 2, nearer the distal hooks. 
Dasijpoda Hrtipes (fig. 45 a) (Andrenidje) has 2 large and slightly curved hooks on the 
membrane of the wing, above the costal nerve and near the distal hooks. 
In Chrysis ignita (fig. 25 a) and bidentata (Chrysedid.e), they are large and situated on 
the upper division of the costal nerve. Ignita, 8 ( <? ?) and 7 ( <? ?) ; Bidentata, 8 ? 
The Tenthredinidjs appear generally to be furnished with sub-1basal 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 Hylotoma rosae, H. ccerulea, H. cyaneo-crocea, H. "A.," or H. "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 wing, 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 draw 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 eood with 
it. 
the base ; so that the distinction appears inapplicable in this family — the only one I have yet seen which requires 
I put it forward only as a quite arbitrary rule, which may be useful if it is necessary to divide the hooks into wo 
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. 
