266 



THE AMERICAN ENTOMOLOGIST. 



tips of elytra, for which reason these (in 

 collections) are so often found lacerated. 

 The ? is often found burrowed into the 

 soil to escape the carressings of the $ , and 

 also for oviposition which takes place there. 



The eggs are very large in comparison 

 with the size of this insect. They mea- 

 sure from 2'S'"'" to 25°""° in length and 

 about 2 """ in width; therefore nearly or- 

 bicular, but, when hastily deposited by spec- 

 imens kept in captivity for some time, 

 they are ellipsoid-oval and much smaller. 

 The chorion is perfectly structureless. In 

 crushing one of the eggs, having no visible 

 primitive discs, the microscope revealed 

 large, shining, white, and flat, non-nucleated 

 discs. I regard them as peripheric yolk- 

 granules formed shortly before the forma- 

 tion of the blastodermic skin (amnion). 

 The greater part of these discs or corpus- 

 cles are of spherical shape, others are more 

 elongate, and even some are of a more 

 irregular form, varying also in size. Acetic 

 acid rapidly dissolves them. 



The eggs are of a yellowish-white waxy 

 appearance, many of them exhibiting the 

 " primitive disc " or " blastodermic skin " 

 through the semi-transparent chorion. 



In the evening of the day on which I 

 received the insects by mail (May 24th, 

 '79) I found eight eggs in the breeding jar. 

 In the morning of May 30th I found three 

 larvae of a black and two of a light pink color 

 on the sand in the jar. The remaining 

 three eggs hatched the following day. 



Larva. — Length (exclusive of proleg and 

 pygidial appendages) of the freshly hatch- 

 larva 6""" (!), width of metathorax 2, 8"""- 

 Three days after hatching (June ist) the 

 oldest larvJE cast their skin. The fresh- 

 ly molted larvae are considerably larger 

 and of a pinkish color, within twelve 

 minutes passing through an iron-grey into 

 the above-mentioned bluish-black color. 



On the evening of June 2d the largest 

 larva measured 17"""- Newly hatched lar- 

 vae walk slowly and by jerks, while older 

 ones run very fast and with more intelli- 

 gence. In casting off the skin, the larva 

 breaks only the occiput of the head and 

 squeezes itself through a median cleavage 



of the three thoracic dorsal segments. On 

 June 3d at half-past seven p. m., a second 

 exuviation took place. These larger larvae 

 are (21""° long, metathorax 6°"" wide) ex- 

 tremely sensitive to light, for, on approach- 

 ing a lighted match in the evening, all 

 the larvfe immediately cover the lower 

 ocelli (Fig. 143, a) with the tibiae of the 

 anterior legs, bending also the head 

 downward. 



The freshly exuviated larvae most plain- 

 ly show the 6 ocelli on each side of the 

 head (Fig. i43,<i'). A dark pigment-zone 

 is formed around the upper ocelli, after 

 the first half-hour of casting the skin, ex- 

 tending downward and around the lower 

 ocelli. The tips of the oral parts also 

 blacken at this time. The larvae are un- 

 usually voracious, but remain quiet before 

 casting. They remain so also for some 

 time after casting. On approaching the 

 side of the head of a larva with a glass- 

 rod that has been dipped in some ethereal 

 oil, they suddenly turn and walk away. 

 This has even been noticed in larvae just 

 before casting, at a time when they always 

 remain quiet on some spot on the sand. 

 The disc near tip of second antennal joint 

 I therefore take for an olfactory organ* 

 in these carrion-larvae (Fig. 143, ^). A third 

 exuviation took place on June nth, but, 

 curiously enough, in all cases the larvae 

 broke through the sternal part of the thor- 

 acic segments. Shortly before and after 

 the third molt, the larvae were found dig- 

 ging into the sand, only coming out for a 

 short time in quest of food. Five days 

 after the last molt all my larvae died. 



Description of larval parts. — Lahntni incised at 

 middle, densely covered with short, stiff bristles. 

 Mandibles without molars. Mando of maxilla 

 with a superior outer series of twelve short, non- 

 articulated processes (Fig. 143, h), the same occur- 

 ring also on an inner inferior series together with 

 ten longer articulated spines. Tip of mando with 

 a smaller penicillus of bristles and a larger pen- 

 icillus near the outer margin of mando. 



Maxillary palpus, three-jointed, first joint trun- 

 cate-elongate, second joint club-shaped, last 

 joints lightly swelled a little behind middle, tip 

 acute, conical with an areola of "sensitive aci- 

 culi." Joints one and two equal, third joint one- 

 third longer. Labial palpus, two-jointed, first 



* I could never notice such a delicate sensibility toward 

 odors in other hexapodous larvae possessing sensitive aciculi or 

 papillae on tips of maxillary or labial palpi. 



