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? coccus (Pl. I., fig. viii), pale yellow, last abdominal segments black; cylindrical; head rounded, and abdomen tapering slowly.
The body is coated with fine hairy spines, and bears dorsally upon the head and abdominal segments rather prominent conical spines. The facial furrow is deep and curred. Median depression of mesothorax forming with furrow a three-sided hollow. The abdominal segments are distinct and incised. The anal appendages, so far as I have been able to observe, are wanting. The last abdominal segment is truncate, cylindrical, dilated somewhat anteriorly. The legs are very well developed, especially the intermediate and posterior pair, which are long and shapely.
gall, length 12 lines, urn-shaped, constricted at base, and at about the height; truncate, summit flat, edge circular, and obtusely crenated, apex rising in form of a small finely pierced cone from the centre, female chamber elongate fusiform, walls comparatively thick.
Habitat Tamworth, collected by Mr. A. M. Lea.
coccus (Pl. IV, fig. vi), orange yellow, four posterior segments of the abdomen a dark brown to black; head and thorax circular somewhat globose; abdomen narrow and tapering; body slightly powdered with mealy secretion; abdomen sometimes surrounded with a cloud of cottony filaments.
The wall of the abdomen is thickly perforated with pin-hole orifices, the softer cephalic portion with peculiar floriform spinnerets (Pl. IV, fig. via). Body covered with hair-like spines. The dorsal margins of the abdominal segments do not exhibit the conical thorn-like spines seen in the other species. The sixth and seventh segments appear as one; thə appendages of the seventh are short, truncate, close together, and straight, but sometimes curled over each other; this segment also bears laterally and dorsally, short stout spines which are arranged irregularly in transverse rowe. Facial furrow long, almost forming a circle. Median depression of mesothorax is longitudinal, constricted, and merging into the facial furrow.
Antennæ inconspicuous, fivo rudimentary joints and few hairs. Legs stoutish, with simple hooks; anterior pair, the trocanter is indistinct; inter. mediate pair, five jointed, longish and prominent, springing from welldeveloped cushions which are rather characteristic; posterior pair retracted to the sides of the insect. Mouth parts small, proboscis discernable but short.
galls generally congregated, forming hypertrophic swellings or tumours (PI. IV, figs. i, ii), which vary in size and shape according to their age, and the number of insects forming them ; appearing on the thicker branches as a series of swellings and constrictions, and upon the small twigs, as globular galls varying from 2 to 3 inches in diameter. The gall made by a single insect forms upon the side adjacent to the insect (Pl. IV, figs. iii to v), and is somewhat hemispherical. The young galls (Pl. IV, figs. ix, x) are smooth, partaking of the nature and colour of the bark, and are without any visible aperture when about three months old. When at the very least twelve months' old an oral plate of bark begins to separate cracking transversely (Pl. IV, fig. iii a), subsequently a second and occasionally a third plate scales off fissuring irregularly. The plates are firmly affixed, and are all thrown off together presumably when an expansion is caused by an increased rising of the say; when removed a cone, the apex of which rises from the bottom of a countersunk depression in the living bark, is esposed. (Pl. IV, fig. i a.) The outer oval plate is not seen in the tumour formed by a number of insects The female chamber, seen by a longitudinal section (Pl. IV, fig. v), is from. 8 to 9 lines in length and 4 lines wide. The plane exhibited is that of an attenuated rhomb. The cavity presents the general appearance of two hollow cones base to base, the ob-cone is countersunk into the ligneous portion of the gall, the apex reaching into the heart of the twig; the upper cone forms a hard woody test of reddish colour, which covers the abdominal segments of the insect, and whose base is inserted into that of the ob-cone. This conical test is partly buried in the sappy part of the wood through which the apex rises into the countersunk depression mentioned above. A rim grows around the outside of the cone at about half its height, and forms the bottom of the countersunk depression.
coccus, 2nd stage (Pl. IV, figs. xi to xii b), active, white, mealy, flattish; length, 16 inch ; greatest breadth at base of thorax, tão inch. Abdomen tapering slightly ; anal segment comparatively large and broad, cleft; appendages set widely apart, deflexed outwards, tips sharp, each bearing dorsally and somewhat towards the inner edge a well-developed conical spine, laterally a long hair-like spine, and ventrally a long sétæ and hair-like spine (Pl. IV, figs. xi and xii). The walls of the abdominal segments are not thickened as in the adult. Dorsally from 10 to 12 very long hairy spines are born upon the last thoracic and abdominal segments. The cephalic portion is bordered by a row of shorter hairs. Antenna appearing as a single ovate joint, the edges slightly serrated. Legs distinct, anterior pair thrown forwards, and the posterior four backwards, as in adults ; upper digitules present, but short. Anogenital ring (Pl. IV, fig. xii a) distinct, six spines, situated on anterior portion of anal segment; mouth parts small situated between bases of first pair of legs. ococcus, adult unobserved.
o galls (Pl. IV, figs. vii and viii), cylindrical, truncate; rim slightly crenate ; length, 2 lines; colour, purple claret; found generally upon the leaves, and rarely upon small twigs.
This interesting insect was first brought prominently into notice by Mr. J.J. Fletcher, Curator of the Linnean Society of New South Wales, who, in company with Mr. C. T. Musson, of the Hawkesbury Agricultural College, discovered two Eucalyptus trees on Ham Common, Richmond, laden with the galls. During the first year of the Department's existence a single specimen was sent in for identification from North Willonghby, and recently I have found it common upon several species of Eucalyptus in the Parramatta district. The formation of the female gall and the lack of the thorn-like spines separate the insect from all other described species, but, until we know really something of this remarkable group of coccids, it is perhaps preferable to place it as a Brachyscelis. Figure xiv, Plate IV, gives a fair idea of how this gall is first formed. A depression, caused, no doubt, by an arrest of development immediately against the insect and the growth of the surrounding tissue, is the first indication. Subsequently a circular wall commences to “shoot" around the insect. This wall I take to be the beginning of the conical test, whilst the depression ultimately forms the remainder of the gall cavity. This initial formation must be soon buried by the hypertrophy of the surrounding bark-tissue and the insect completely shut in. At some future date I hope to be in the position to stato definitely the duration of the life of this species, and I believe that as our knowledge of it increases it will prove to be of as great an interest as any of the gallmaking Coccidide previously described.
I have received from Mr. A. Rudder, Forest Ranger in charge of the Port Stephens district, a very interesting gall (Pl. III, figs. iv to vii), which gros