Scudder. 130 October 21, 



Mr. S. H. Scudder presented, on behalf of Miss Flint of 

 Chariest own, several nests of trap-door spiders found in 

 Mentone, France, together with specimens of the insects 

 themselves. 



Cylindrical holes in the earth, serving as nests, are made by but a 

 single family of spiders, commonly known as Tarantulas, and are of 

 four types: a simple tube, without covering; a simple tube with a 

 silken lid, either thin, like a wafer, or thick, like a cork; a simple 

 tube with two lids, always wafer-like, one at the summit and another 

 part way down the tube, the latter resting against the side of the 

 tube, when not in use; and a branched tube, which is a modification 

 of the third type, made by constructing an upwardly receding branch 

 to the tube, behind the point where the inner lid falls when not in 

 use; in this case the inmate, finding resistance useless against the en- 

 croachments of an enemy which has effected an entrance to the tube, 

 retreats up the branch and allows the lid to fall and conceal the 

 opening, baffling the efforts of the intruder, who vainly searches the 

 bottom of the tube for his victim. 



Nests of the simplest type are found in our own State, while sim- 

 ple tubes with cork-like lids are made by a large Californian spider. 



Prof. A. Hyatt gave an account of his recent studies of 

 the larvae of some forms of Ascidia. 



The larva of Cynthia is not unlike a very young tadpole in exter- 

 nal outline, having an egg-shaped body, with a tail of considerable 

 length, and this tail surrounded by a continuous fin of extremely 

 transparent membrane. This fin had been described by Prof. E. S. 

 Morse, and certain marks in it described and figured as rays. Such 

 rays as had been described certainly were present, but a closer ex- 

 amination of several hundred larvse of Cynthia carnea seemed to 

 show that no differences existed between the rays and the adjoining 

 parts of the same membrane. The appearance of rays was due en- 

 tirely to permanent folds, which occur when the animal is seen in its 

 usual position from either side, but which may be considerably al- 

 tered in form, number and position, by varying the position of the 

 animal. "A technical point like this seems to be of but slight impor- 

 tance, but since this fin has been compared by a late author with the 

 fin of a fish, it becomes at once of great interest to ascertain the 

 exact nature of the rays, and whether they are really supports ex- 



