1868.] 



369 



[Packard. 



boily is so bent upon itself that the extremities of the si>cond maxilltB 

 just overlap the tip of the abdomen. 



Tlie front of the head is now still farther differentiated. The 

 supra-clypeal piece seems to be merged with the ophthalmic ring, 

 the sutures between them having disappeared. The insei'tions of the 

 antennas are removed higher up to just in front of the eyes, or rather 

 the eyes have dropped down, as it were. The clypeus is broad and 

 large, and the bilobate labrum is separated from it by a suture. The 

 mandibles and maxillne are still tubercular in 

 shape, the teeth of the former not yet appear- 

 ing. The two limbs of the labium are now 

 placed side by side, with the prominent spi- 

 nous appendage on the outer edges of the tip. 

 These spines are the rudiments of the labial 

 palpi. 



The legs are long and bent partially back 

 on themselves; at the angles partially articu- 

 lated. The femoro-coxal joints are very dis- 

 tinct, the tarsi are directed upwards and the 

 two claws are simple, straight, and equal in 

 size. The tip of the abdomen ends in two 

 unequal pairs of stylets, terminating in a long 

 bristle. 



6, a. (Fig. 4.) The general form of the em- 

 bryo at a still later period, on being taken 

 from the egg and straightened out, reminds 

 us strikingly of the Thysanura, and, in these 

 and other respects, shows quite conclusively J^^.^f^^. ''^"^^^^--^^^-j^dy 



that tlie Podur^e and hepismas, and allied crosses the main trachoa, 

 , -1 I ^ r /.going through the yolk 



genera, are embryonic, degraded forms of massTnowrestrict.dto the 

 Neuroptera, and should therefore be consid- po'^^'^resjon Atx, the 

 ^ . _ tracheae send off numerous 



ered as a famny of that suborder, oeen lat- branches around an en- 

 erally, the body gradually tapers from i^.^'^^^^^^^^^otu.^ ir^x^.rme 



The embryo taken from 



(colon ), where the blood is 



The aerated ; bettor seen in 



. flg.5. The abdomen con- 



At sists of eleven se;;;ments, 



large head to the pointed extremity. 



body is flattened from above downwards 



this'stage the appendages are still closely ap- the last being a minute tri: 



^ 1 1 o J f angular piece. 



pressed to the body. 



7. This period occurs just before the exclusion of the embryo, and 

 the limbs are still laid along the body. They, however, with the mouth- 

 parts, stand out freer from the body. The labium, especially, assumes 

 a position at nearly right angles to the body. The antennce, mandi- 

 bles, and maxillaj are now free, and have taken on a more definite 

 form, being like that of the young larva, and stand out free from the 



24 MAV, 186S. 



PROCEEDINGS. B. S. X. H. — VOL. XI. 



