174 



THE AMERICAN ENTOMOLOGIST. 



NOTES ON THE EGGS AND LARVAE OP AN 

 UNKNOWN DRAGON-FLY. 



\V. R. GERARD, 



In the month of July, 1878, while row- 

 ing on a small lake at Willowsmoe, on the 

 Southern Catskills, my attention was at- 

 tracted by a number of long gelatinous 

 egg-masses of some animal unknown to 

 me, and which were attached, in bunches 

 of from 30 to 40, by one of their extremi- 



[Fig. 77.] 



^Mk^ 



5mall portion of Egg-mass of Dragon-Fly, probably Diplax 

 (after Gerardj. 



ties, to the stems of Potamogeto?i, and 

 floating horizontally near the surface of 

 the water. Each string (Fig. 77) was 

 cylindrical ; about one-eighth of an inch 

 in diameter ; 12 to 15 inches long; opal- 

 escent by reflected and transparent by 

 transmitted light ; and, being continuous 

 throughout its whole length, was appar- 

 ently the product of a single individual. 

 There was such a difference in the state 

 of development, however, of the eggs 

 taken from the same or different parts of 

 the string as to make a subsequent chro- 

 nological study impossible. The yelks, 

 broadly elliptical in outline, and pale yel- 

 low in color, were 

 each inclosed in a 

 hyaline ovoid 

 membrane, which 

 was apiculate at 

 its broad extrem- 

 ity (Fig. 78). The 

 eggs were placed 

 at such an angle 

 in the mass as to 

 cause their broad 

 ends to point out- 

 wards and towards the free end of the 

 string. As nearly as I could count, there 

 were about 500 eggs to the inch. Being 

 ignorant of what I had to deal with, I 

 assumed, from analogy merely, that these 

 egg-masses were the product of some ba- 

 trachian allied to the toad. On visiting 

 the locality very early the next morning 



Dragon-fly eggs, enlarged (af- 

 ter Gerard.) 



after the discovery, I was surprised to find 

 that the strings had all disappeared from 

 sight ; but later in the day, when the sun 

 was high, and the water warm, I found 

 them again, floating as before. It seems 

 that at night the strings sink and hang 

 vertically alongside of the plant to which 

 they are attached, and are thus hidden. 

 I could not ascertain the cause of this 

 phenomenon, although I observed it fre- 

 quently thereafter ; but it is certainly a 

 wise provision of Nature to ensure of the 

 eggs in the whole extent of the string re- 

 ceiving the full rays of the sun. I brought 

 one or two of the strings home with me, 



[Fig. 79.] 



Dragon-fly larva : , a, just before escaping from gela- 

 tinous surrounding ; b, just after escaping, all legs but one de- 

 tached (after Gerard). 



intending to study the development of the 

 as yet unknown animal, ab ovo, and for 

 this purpose put them in a large tumbler 

 of water in my window, where they re- 

 ceived the rays of the sun. Owing to the 

 fact, as above stated, that the eggs were 



