326 Miscellaneous. 



numerous islets of annular muscular fibres which must act after the 

 fashion of a sphincter. 



The endoderm is composed of a cellular layer, which covers the 

 inner surface of the mesoderm and extends over the septa. 



The structure of the tentacles is similar to that of the walls of 

 the body. These organs, however, are characterized by the pre- 

 sence of a layer of longitudinal muscular fibres situated beneath the 

 ectoderm. 



The septa originate from the mesodermic layer of the column. 

 Their axis is a fibrous tissue covered with a layer of longitudinal 

 muscular fibres. Upon one of its surfaces each septum bears a 

 series of longitudinal folds, the totality of which represents a sort 

 of fibro-muscular bundle. 



The oesophagus, resulting from the turning back of the two pri- 

 mitive lamella?, necessarily presents the structure of the wall of the 

 body. The exterior cellular layer contains peculiar glandular 

 elements. 



In Cerianihus and the Actinic? the reproductive elements origi- 

 nate in a sort of doubling of the fibrous layer of the septa — that is 

 to say, in the mesodermic region. — Comptes llendus, August 25, 

 1879, p. 452. 



Notes on the Marriage-flights of Lasius flavus and Myimica lobi- 

 cornis. By the .Rev. H. C. McCook. 



The author remarked that the first-named ant is one of the most 

 familiar objects in nature. Its small dusky-yellow workers may be 

 seen in every American lawn, walk, field, and yard, throwing up 

 their fragile moundlets of sand pellets, and swarming upon particles 

 of fruit, crumbs, bones, dead insects, and all manner of sweets. It is 

 quite cosmopolitan in its distribution, and is well known in Europe. 

 The following observation of the annual marriage-flight of the sexes 

 was made September 5, 1878, in the vicinity of Philadelphia. The 

 nests observed were located directly in and on the grassy border of 

 a trodden path in a farmyard. At 4 p.m. the males and females 

 were seen coming out and re-entering the gate, amid great excite- 

 ment on the part of the workers. The females particularly were 

 followed by workers who "teased" them occasionally by gently 

 nipping them with their mandibles. The flight of the young queens 

 was, with few exceptions, made from the top of stalks of grass, 

 where they clung for several minutes, poising themselves, spreading 

 their wings, and swaying up and down. Even to these elevations 

 the workers followed them, hastening their flight by occasional 

 " nips." "When the queen rose in flight, there was no evidence of 

 feebleness or inexperince, except, in some cases, a slight tendency 

 to a zigzag course for the first few yards. The flight was then, and 

 in most cases from the very first also, strong and in a straight 



