1871.] 395 [Emerton. 



from the anterior part of the head along the ventral surface to the 

 post-abdomen, dividing the whole embryo into two parts (Figs. 13 and 

 14). 



Aug. 4 the segments of the abdomen increased in number from 

 two to six, and the post-abdomen became narrowed and constricted 

 into three divisions and turned down against the abdomen (Fig. 15). 

 Each segment of the abdomen now showed two pairs of appendages, 

 the bourrellets ventraux of Claparede, one pair on the edges of the 

 transparent band, the other a little removed from it in line with the 

 legs. Twelve hours later, when the separation of the ventral portion 

 had exposed the under side of the body, between the legs a pair of 

 similar appendages could be seen on each segment of the thorax, on 

 the edges of the transparent band (Fig. 16). 



Aug. 5 the turning of the embryo began. The transparent ventral 

 band had widened at the posterior part of the thorax to nearly the 

 diameter of the body. The post-abdomen had turned down along 

 the ventral surface of the abdomen. The thoracic portion now di- 

 minished in size while the abdominal portion increased, turning grad- 

 ually under the thorax between the legs. At this stage the under lip 

 appeared in the anterior end of the transparent band, which now 

 reached to the top of the head (Fig. 18), but in the next three days 

 descended below the mandibles (Fig. 19). The position of the eyes 

 was indicated by two pairs of white spots (Fig. 18) on the front of the 

 head, and of the dorsal vessel by a white line from the head to the 

 front part of the abdomen (Fig. 17). 



Aug. 6 the thorax continued to diminish and a constriction began 

 between it and the abdomen. 



Aug. 10 the eyes were distinctly seen, and the mandibles had come 

 together in front of the mouth. The legs entirely covered the ven- 

 tral surface of the body. 



Aug. 1 1 the eggs began to hatch, the outer envelope cracking along 

 the lines of the limbs and not coming off entirely for two days. The 

 first moult took place Aug. 16. 



Mr. B. P. Mann read portions of an account of the "White 

 Coffee-leaf miner", Cemiostoma coffeellum, which he had 

 prepared for the American Naturalist. 



Mr. W. T. Brigham called attention to a mounted speci- 

 men of the mute swan, Cygnus olor, presented by the Hon. 



