In developing a general view of the changes in the neuration of the lepidopterous wing, the mass of detail in any one paper may obscure, for the reader, the statement of the assumed plan of progression. This seems to be, briefly, a simplification of the longitudinal systems of veining, and attained through a process of reduction. Where this progress would interfere with the serviceableness of the organ, the dormant tracheæ in the tegument may, in speciar cases, develop accessory veins, such as the humeral spurs of the Lachneids, the cross branches and extra veins in Tineides, and, as I have suggested, the so-called precostal spur (at one time vein I. of Comstock) on the hind wings of the diurnals. The cubital and discal cross-veins may be, however, survivals of a former system of cross-veins, since we apprehend them in various stages of retrogression. But they may be also what I call sub-secondary: produced at one time to be abandoned at another. Still, this latter is a rather violent theory. It is better to adopt the view that there is a general simplification going or controlled by mechanical causes and subsidiary to tlie habit and changes in habit of the organism, and which includes these two cross-vetns.

In reference to my previous paper (page 209), Mr. Louis B. Prout kindly draws my attention to the fact that Duponchel, Lep. Ent., March, 1829, also selects didyma as type of Apamea, Ochs., 1816. While it is gratifying that I had come independently to the same conclusion with regard to this type, I cannot follow Duponchel's selection in other cases. I merely state the fact here, reserving details for a later occasion.

It further appears from Mr. Prout's researches that Curtis, who publishes later than Duponchel, viz., in May, 1829, “chooses chrysographa” as type of Apamea.

In Trans. Am. Ent. Soc., 20: 276, 1893, I described Nomada Sayi from eight female and fifteen male specimens. At present I have fortyfive female and ninety male specimens which I have referred to this species, but which I now propose to describe under the three following names:

Nomada Sayi, Rob.— ♀. Mandibles simple, antennæ long, joint 4 longer than 3 or 5, as long as 12; or nearly so, pygidium rather broadly truncate; scutellum sub-bilobed, prominent; enclosure of metathorax coarsely reticulated at base, finely roughened beyond; head and thorax closely and coarsely punctured; abdomen shining, rather sparsely and finely punctured; ferruginous, the scape, front and middle legs, tubercles and tegulæ, more yellowish; about antennæ, about ocelli, occiput, band on mesonotum, middle of metathorax sometimes, band from wings to middle and hind coxæ, base of femora behind more or ress, sometimes hind metatarsi, base of abdomen, sometimes apical margins of segments more or less, and sutures, generally blach or blackish; segments 2 and 3 of abdomen with a yellow spot on each side; wings hyaline, marginal cell and apical margins clouded, basal nervure ending before transverse median. Length, 6–8 mm.

The majority of the species falling in this subfamily are usually smaller and much less conspicuous than those in the other subfamilies, and with totally different habits. None are true diggers, but, on the contrary, build small oblong, or oval, clay cells, beneath the loose bark of old trees, under stones, or in crevices in old stone walls, etc., not unlike some of the Potter wasps (Eumenidœ).

The group comes evidently nearest to the Pepsinœ, the females having, as in that group, a transverse grooved line, impression or emargination on the second ventral segment. From that group, however, it is at once separated by the difference in the legs, the hind tibiæ being smooth, never serrate or spinous, or with a longitudinal ridge, but, at the most, with only a few very minute, scarcely perceptible spines.

The larvæ are universally borers, but in the choice of food-plants there is the widest diversity; some bore through and devour solid wood, as do the larvæ of the Cossids; some prefer the pith of woody stems; others are found in the superficial woody layers; still others affect the roots of plants both woody and herbaceous, or are sometimes to be found in the borings made by other insects, as is the case with Memythrus tricinctus, Sesia pictipes, S. scitula, and others. The larvæ are yellowish or dirty white, beset with only a few short hairs. The head and cervical shield are chestnut brown. They hibernate in various stages of growth, but do not overwinter in the pupal stage, as far as the species of the northern States are concerned. The larvæ of Melittia satyriniformis hibernate fully grown in the cocoons. When fully developed they spin elongate oval cocoons composed of chips cemented together by a gummy secretion or silk. The cocoons are formed in the burrows or in contiguous places.

The following table is intended to serve as a means of separating the species of the genus Agapostemon, Smith, occurring in Colorado: Body green or blue-green.

About the time that Lord Walsingham's valuable paper on Acrolophus and Anaphora appeared (Trans. Ent, Soc., Lond., 1887, 137–173), Mr. Beutenmüller was working on the same group; but neither author has since attempted to recognize the species named by the other, so far as I am aware. In Prof. Smith's List Lep. Bor. Amer., 1891, the group is recognized as a family—Anaphoridæ—but this can hardly stand. The genera will fall in the Tineidæ, in the more restricted sense (see Walsingham, Proc. Zool. Soc., London, 1897, 139–175).

Xylococcus quercus, n. sp. (Plate 7, figs. 1 and 2.)

Egg quite large, of a light orange colour.

Young larvœ dark orange-red, active, body broadly oval, abont ⅔ mm. long. Legs and antennæ light brown, well developed. Antennæ short, 6-jointed. Joint 1 stoutest, joint 6 longest, and joint 4 shortest. Formula: 651234. Joints 2 and 5 with three bristles. Joint 6 with numerous long stout bristles. Legs moderately long, with femur quite swollen. Tarsus longer than tibia. Digitules of tarsus fine hairs; those of claw long stout clubs curved upwards. Each segment of abdomen bears a backward directed short stout spine. On each side of anal tube is a long fine bristle. Anal tube large, with numerous stont spines. Stigmatal tubes well developed.

The status of Professor French's Gastrophilus epilepsalis, described in the September number of this journal, has interested me especially, as I am preparing a new catalogue of North American Diptera.

I am convinced that it was decidedly premature to assign a specific name to this larva. In the first place, it was very small and immature, and the earlier larval forms of Oestridæ are much less known than the later, so that we do not possess the data that would enable us to separate this species, for instance, from G. nasalis.

On page 54 of the current volume of the Canadian Entomologist, I called attention to the sudden and almost total disappearance of this species at Wooster, Ohio, where it had for several years been excessively abundant, even up to the latter part of August and early September of last year, 1899. This abrupt termination of the period of activity was at the time attributed to the effect of a parasitic species, Ichneutes, sp. ?, which had in the meantime become also excessively abundant.