44 JOURNAL OF THE [January, 



female, and parasites of the same ; Thalessa atrata, Fab., male 

 and female ; and T. lunator, Fab., male and female : by J. L. 

 Zabriskie, 



3. Pond-life ; Plumatella repens, and Floscularia ornata : by 

 Stephen Helm. 



4. An unknown and curious form of insect-life, found upon 

 grass in New Jersey : by James Walker. 



5. A piece of felted fungoid mycelium, an inch thick, found 

 on the floor of a wine-cellar at Newburgh, N. Y.: by F. W. 

 Leggett. 



6. Section of Peridotyte, with transparent, yellow Olivine : 

 by T. B. Briggs. 



7. Foot of the fly, Eristalis tenax : by L. Riederer. 



is. Sections of the foot-cushions of the same: by L. Riederer. 



9. Sections of spines of Echinus : hy J. D. Hyatt, 



Mr. Hyatt described his method of preparing sections of 

 spines of Echinus, saying, that it is much easier to grind down 

 a number of such sections at one time, than to grind one singly. 

 He fills a glass tube with spines, cementing them in place with 

 balsam, and then, by means of a circular diamond-saw, slices 

 both tube and contained spines into thin disks. A number of 

 these disks are cemented by balsam to a glass slip, and all are 

 ground down together. In order to successfully turn them over, 

 to continue the grinding, they are cemented to the first slip with 

 thin balsam. The slip, to which they are to be transferred, is 

 supplied with thick balsam and inverted over the sections, 

 whereupon, with proper manipulation, the sections will leave the 

 first slip and adhere to the second. He mounts seven or eight 

 sections of spines under one cover, returning them to their de- 

 sired positions, if displaced in mounting, by inserting under the 

 cover a needle, ground flat and very thin upon an emery-wheel. 



Mr. Zabriskie said, that the insect, from which his exhibit 

 was taken, was captured ovipositing in the hard, decorticated 

 wood of a standing Silver Maple, Acer dasycarputn, Ehrh. The 

 ovipositor was inserted about one-half of an inch into the wood,, 

 and it required considerable force and much patience with the 

 help of a forceps to extract it, without entirely demolishing the 

 ovipositor. Even with the greatest care the terminal barbs were 

 somewhat injured by the operation. The shaft and the depress- 

 ions between the barbs of this ovipositor polarize brilliantly. 



