THE CANADIAN ENTOMOLOGIST. 289 



appear to follow that the nymphs may bury themselves in the mud and 

 remain in the dry capsules for a long time unharmed until rains return. 

 Cases were cited of Dip/ax riibiacndula and D. obtricsa industriously 

 ovipositing among the grass of a dried-up pond, and of Lestis triangularis 

 ovipositing in plants in similar places. 



Mention was also made of the capture of more Southern species in 

 the Mauraee Valley. 



7. A valuable morphological paper was presented by Miss Agnes 

 M. Claypole, of Wellesley, Mass., on " The Appendages of an Insect 

 Embryo." The form used was identified as Amirida maritima, Guerin, 

 and was collected under stones on the beach at Woods' Holl, Mass. It 

 belongs to a wingless group of Insecta, the CoUembola, and is the first 

 form of the group as yet studied in microscopic sections. 



The cleavage of the egg is complete, holoblastic, a character belong- 

 ing to this group of insects only, all the others having central cleavage. 

 The appearance of the appendages takes place very early, the antennae 

 being the first of the series ; following the antennaj is a pair of very small 

 appendages on the body segment, carrying what is well known to be the 

 third brain segment. Behind these, the mandibles, ist maxillae, and 2nd 

 maxillae appear successively, in turn followed again by the thoracic 

 appendages. All of these organs increase in size excepting the small 

 pair on the third segment, which remain unchanged till the mouth-parts 

 and antennae have assumed almost distinctive characters. Then these 

 small ones begin to grow as a ridge down each side of the three pairs of 

 mouth-parts and finally form a wide platelike appendage enclosing the 

 mandibles and second maxilU^ entirely. In the adult the mouth-parts 

 are known to be enclosed in a tube, or to be " drawn iri," as the condition 

 is usually described. 



If, as is generally acknowledged, the insect antennas are considered 

 homologous with the first pair of antennae of the Crustacea, a point of 

 considerable interest is developed. The appendage of the third brain 

 segment has been found in many insect embryos, but in all cases is a 

 purely embryonic structure; it disappears before hatching. Among terres- 

 trial Crustacea — the wood lice, for example — the second pair of antennae 

 is reduced to an extremely small size. Hence Anurida is an interesting 

 form showing an insect in which the second pair of antennae of the Crus- 

 tacea is present, and functional in the adult ; the function, however, 

 is completely changed. D. S. Kellicott, 



Secretary Section F. 



