382 WHEELER. 
DESCRIPTION OF PLATE XIX. 
Doryphora decemlineata. 
Fic. 72. Embryo shortly after the appearance of the appendages, unrolled and iso- 
lated. 0, stomodeum; a, proctodeum; /, labrum; 4! to 63, three brain segments; 
og! to og, three segments of the optic ganglion; of! to of%, three segments of the 
optic plate; @ to 2°, five pairs of invaginations which form the tentorium; 7 to 7, 
tracheal invaginations; the two last pairs 7° and 2, either disappear or form the 
openings of the sexual ducts; @/, antenne; md, mandibles; mx) and mx, first and 
second maxilla; /! to £%, three pairs of thoracic appendages; ¢c, commissure con- 
necting the two ganglionic thickenings g* of the intercalary segment; g/, ganglionic 
thickening; mzs/, Mittelstrang thickening; mfg! to mpg*, three Malpighian vessels. 
Fic. 73. Embryo just after the closing of the amnion and serosa (s7) unrolled and 
isolated. a, oral, x, anal end of the gastrula; fc/, procephalic lobe; m.«?, second 
maxilla; #1 to #, three thoracic appendages; cf, caudal plate. 
Fic. 74. Ventral view of embryo, the lateral walls of which have embraced half 
the yolk; references same as in Fig. 72. 
Fic. 75. Lateral view of embryo ready to hatch. a, antenna; ¢%, mesothoracic 
spiracle; 7! to ¢18, abdominal spiracles; /sf, first hatching-spine. 
Fic. 76. Sagittal section to one side of the median line through the tail of embryo, 
Fig. 72. am, amnion; s7, serosa; mpg! and mpg%, first and third Malpighian 
vessels; ecd, ectoderm; msd, mesoderm; ev¢, forward growing band of entoderm; 
ent', mass of entoderm left under the end of the proctodzeum. 
Fic. 77. Transverse section through the second pair of Malpighian vessels (mg) 
of the same embryo. x, proctodzeum; other references same as in Fig. 76, 
Fic. 78. Median cross-section through an egg containing an embryo a little older 
than that represented in Fig. 72. The section cuts the embryo at two places. That 
with the entoderm (e/) belongs to one of the last abdominal segments, that withou* 
entoderm to one of the basal abdominal segments. 27, neural thickenings; ecd and 
ent, ectoderm and entoderm; s/m, sm, splanchnic and somatic mesoderm, inclosing 
the coelomic cavity; cd, cb, cardioblast cells. 
Fic. 79. Cross-section through the middle of the proctodzeum of an embryo some- 
what younger than that represented in Fig. 74. x, proctodzeal cavity; c/, coelomic 
cavity; g/, ganglion; mst, Mittelstrang; mpg! to mpg’, Malpighian vessels sur- 
rounded by mesodermic elements. 
Fie. 80. Cross-sections through the sexual orifices of an embryo in the stage of 
Fig. 74. go, go, openings of efferent ducts; remaining references as in preceding 
figures. 
Fic. 81. Surface view of two eyes (corresponding to eyes V. and VL. of Aczdéus as 
described by Patten). 7, large nucleus in the centre of each eye. 
Fic. 82. Median sagittal section through an embryo in about the stage represented 
in Fig. 73. @m and sv, amnion and serosa; 0, point at which the anterior end of 
the embryo passes into the amnion; /, point at which the posterior end passes into 
the amnion; sf, stomodzeal depression; x, point near which the proctodzum will 
appear; #/1, f/*, anterior and posterior thickenings of the inner layer; from which 
the entoderm, ent}, ent?, originate. msd, mesoderm; mx! and mx, first and second 
maxille; 4! to £3, legs; c, cells which entered the amniotic cavity. Under the two 
thickenings 7/1, f/?, are seen the peculiar degenerating nuclei passing into the yolk, 
which has become segmented. 
