Adult female greyish, elongated, segmented. Rudimentary antennæ visible. Abdomen ending in two lobes with a median depression: several scaly and serrated processes, and some spiny hairs. Five groups of spinnerets: uppermost group, six to nine orifices; upper side groups, ten to fourteen; lower pair, fifteen to twenty: several single spinnerets. Male unknown. Habitat--On _Phymatodes billardieri_, Wellington; Auckland. In outward appearance the female resembles _M. pomorum_, but the puparium is quite different, and the abdominal characters also differ. 19. Mytilaspis pomorum, Bouché. _Aspidiotus pomorum_, Bouché; Ent. Zeit. Stett., 1851, XII., No. 1. _Aspidiotus conchiformis_, _auctorum_; _nec_ Gmelin, Syst. Nat., 2,221. _Aspidiotus pyrus-malus_, Kennicott; 1854, Acad. Science of Cleveland. _Aspidiotus juglandis_, Fitch; Ann. Rep., N.Y. State Ag. Soc., 1856; _nec_ Signoret, loc. cit., 1870, p. 95. _Aspidiotus falciformis_, Bärensprung; Journ. d'Alton et Burm., 1849. _Mytilaspis pomicorticis_, Riley; Fifth Rep. State Entom., Missouri, p. 95. _Mytilaspis pomorum_ (Bouché), Signoret; loc. cit., 1870, p. 98. N.Z. Trans., Vol. XI., 1878, p. 192. The common apple-scale. (Plate V., Fig. 5.) Female puparium usually brown,[M] sometimes white; elongated, mussel-shaped, convex, slightly curved, sometimes straight; length, about 1/10in. [M] Dr. Signoret says, "brun noirâtre." Mr. Comstock calls it "ash-grey." In reality the colour varies somewhat with that of the bark of the tree. Male puparium not known in New Zealand. In America it is stated[N] to be small, "straight or nearly so, and with the posterior part joined to the remainder of the scale by a thin portion which serves as a hinge." [N] Comstock; Rep. of Entom., U.S. Dept. of Agric., 1880, p. 325. Adult female greyish, yellowish, or white; elongated, segmented. Rudimentary antennæ present. At the edge of each segment two or three strong spines. Abdomen ending in two large lobes, with two others much smaller on each side; the median lobes are trifoliated. Between and beyond the lobes some spines. Five groups of spinnerets; numbers of orifices variable (see below); a few single spinnerets. Male unknown in New Zealand and Europe, doubtful in America. Colour stated by Riley (Fifth Missouri Report, p. 95) as "translucent corneous-grey." Habitat in New Zealand--On apple, pear, plum, peach, apricot, lilac, ash, thorn, sycamore, cotoneaster, and other plants, _passim_. An introduced European species, known in America and elsewhere as the "oyster-shell bark-louse of the apple." It is the commonest, apparently, of the Diaspidinæ; and does great damage in orchards.