414: PS 2"CHE. [November--December I89o. homology. It is utterly unphilospho- cal to accept without the clearest proof EXPLANATION TO BASE FIGURES. such a structural modification as this Fig. r. Si2blono2bkora avenae, a, beak change in position of the mandibles b, bristles ofmouth---"mandibles" and"max- would require, and the modification of illae;" c, antenna of winged viviparous the ordinary labium into a beak of this female. character is a process that ought to be Fig. 2. A2bhis brassicae, a, antenna of proven. It seems to be assumed that the wingless forms; b, antenna of winged vivi- "labium" of the hemiptera is the same parous female c, beak of young lice; d, beak of mature, winged form. as the "labium." of the diptera, e. g. Culex, and if this is so, I have a paper Fig. 3. Ahhis cucumeris, a, antenna of now in press, in which I claim to prove winged viviparous female; b, beak of wing- that this "labium" in the diptera is less forms. really only a modified galea, or a max- Fig. 4. Myzus cerasi, a, 3rd; b. 5th; illary structure. I hope to prove some c, 6th joint of antenna of winged viviparous time in the future, when I can get the female. necessary material, how this rnodifica- Fig. 5. AibMspersicae'nier" a, antenna tion of the hemipterous mouth came of immature forms, joints 5 and 6; b, 3rd; about, and that the mandibles do not, c, 4th; d, 5th; e, 6th joint of antenna of habitually, become internal mouth winged viviparous female; f, sensory pit from front;g; same from side. structures so long as there are other organs enough more naturally situated. NOTES ON TWO SPECIES OF DATANA WITH DESCRIPTIONS OF THEIR LARVAL STAGES. BY HARRISON G. DYAR, RHINEBECK, N. Y. Of all the clogely related species of species differ, or rather tend to differ, this genus, the two which approach in other points beside the brightness of each other the most nearly and are most the costal shade, namely, in the more difficult to distinguish in the imago entire outer margin of the primaries, state, are D. rezajor and D. drexelii, and the darker more even coloration of I have elsewhere called attention to the the wings of D. major. main feature by which they are to be The size is the same in both species, distinguished, which, after all, is only there are no markedly distinctive male a matter of degree of coloration. The genital characters, and the lines and November--December 89o.] PS 1Ctt2. 415 spots are arranged in the same manner; predominance of yellow about the pro- in fact, there is no absolutely constant thoracic and the 8th, 9th and oth ab- difference, either in structure, markings dominal segments,* and this might serve or coloration, between the two so far as as an excellent protection, in that the I have been able to observe, and I have bunches of yellow striped larvae with no doubt that specimens may occasional- their extremities elevated in their cus- ly occur which it would not be possible tomary position, resemble the little to refer positively to one species or the clusters of flowers of the Witch-Hazel other by an examination of the imago with their linear yellow petals, which alone. It would at first seem that these begin to blossom in September, iust as species must be more closely related than the larvae become conspicuous. What others in the genus, perhaps hardly protection, if any, their coloration affords yet distinct; but when we consider the on the Deerberry, their other food-plant, larval stages, it is at once apparent that I am unable to say, as they occur ahnost they are widely separated, more widely, exclusively on the Witch-Hazel in this in fact, than many other species of .Data- vicinity. (Rhinebeck, N. Y.) na which are readily separable in the But as to D. major its curious spots imago state. This difference would seem do not resemble anything so far as I can to indicate rather a long inherited simi- see. It is to be noted, however, that larity between the moths than very recent the habits of the two species differ, for derivation from a colnmon ancestor. while D. drexelii are always gregarious, While the moths, it may be, have re- D. major, when they do not separate mained constant to their former type, entirely, feed farther apart, and tend to or undergone a similar development, the scatter more in the last stage than al- larvae have diverged greatly, which most any other species, and the change would seem to correspond to the gen- in ornamentation from lines to spots, eral rule in lepidoptera, that the larvae which they undergo in the last molt, are often the first to vary. The eggs of D. may be of use to them with their major and Z). drexelii differ markedly changed habits. the larval differences appear in the first DATANA MAJOR,. G. and are and stage kept up intensified 'ffg'. Sub-pyriform, of less diameter throughout the larval and period, only and cylindrical for a short distance at the when the is pupa stage reached, does top, recalling the structure of D. palmii; the close resemblance observed in the flattened at base or a little hollowed; moths begin. The cause of the diver- evenly flat on top with a sharp angle in the at gence larvae,especially maturity, between top and sides. Color uni- is not obvious, in the very particularly form sublustrous white, a rather peculiar ornamentation of D. major, which differs from that of all of the In this article, have followed the nomenclature other Dalana larvae so far known. used by Dr. Packard for the larval segments, as it is not possible to describe intelligently the markings nf D. drexelii is abnormal only in the .Dalana by the usual method. PSCHE. [November--December x89o. Spiracles velvety black. Hair white, days; and stage, 6 days; 3rd stage, 8 rather long, beside numerous fine, short days; 4th stage, 9 days. black hairs, all growing from minute FooD-eLaNT: Andromeda ligustri- black tubercles. Length of larva at maturity 60 mm. The form of this Larvae from Ulster Co., N. Y. larva with canary yellow bands and spots did not occur in any of the examples DATANA DREXEL'If, -[y..Edw. fl'om which these notes were made (a 2'gg. On the type of 29. ministra. brood of 55 and another large brood ob- Subcylindrical, of a little greater di- served in the field). I have formerly ameter near the bottom than near the found a few yellow ones among a brood top vertex rounded; base nearly flat. ofwhite spotted Z). major, and occasion- Color shiny whitish, the circular lid-like ally a brood entirely yellow. Though top very white and shiny, with a central the difference in coloration is very small round black spot. Diameter "7 marked between the two forms, it is ram. In hatching, the larva eats away evidently, from its mode of occurrence, the lid, and emerges from the hole thus only a variation. A similar variation formed. occurs in D. palmii* and less markedly First stage. Head rounded, black, in Z). contracta. shiny; width "5 ram. When newly l-uiba. Formed in a subterraneous cell. hatched, the larva is scarcely dis- In shape it is robust, cylindrical, thickest tinguishable from 29. major. The centrally, and rounded to the head cases anal feet are rather long and elevated. distinct; a slight creased elevation be- Body sordid yellow, cervical shield, anal tween the eyes. Abdominal segments plate and feet, blackish. A number of slightly tapering cremasters, two, very short hairs fiom the head and fiom short, not well separated, each with three about six rows of small blackish tuber- spines, the posterior one the longest, but cles which are larger in proportion than often two, or partly aborted. Cases in the subsequent stages. As the stage creased, body coarsely punctured, very advances, the body becomes reddish finely in the movable sutures. Color with four lateral stripes on each side dark or blackish mahogany. Length 25 and three ventral, about as wide as the mm., width 9 mm. This stage lasts intervening spaces, dull yellow and con- through the winter and the species is fluent posteriorly. During this stage, single brooded. The duration of the lar- the larvae eat the parenchyma in the val stages was as follows: st stage, same manner as 29. major. I have not observed, but probably about five estimated that a single larva eats about would like to call attention to the relationship 9 sq. ram. of Witch-Hazel leaf. that evidently exists between D. palmii and Z). major, Second stage. Head black and shiny They alike in egg structure, in the feature of bico. lorous larval hairs (which does not in any other with a few hairs, width t. ram. Body species to my knowledge), in coloration of heaa an.d brown, stripes dull yellow, narrower lines and in the slightly scalloped forewings of the moth. than the intervening spaces, extending November--December 89o. ISUCtIE 419 from the cervical shield and the anterior tured. Clypeus and labrum somewhat edge of the prothoracic segment to the wrinkled. Color shiy black, the an- anal plate and becoming a little con- tennae and palpi white-ringed, their bases fluent there. Cervical shield, anal greenish. Width 5'4 ram. Body black, plate, thoracic and anal feet and the cervical shield honey yellow, anal plate, abdominal feet outwardly black, tIir thoracic and anal feet and the abdomi- short and pale.