1871.] 393 [Bicknell. 



Section of Microscopy. December 13, 1871. 



Mr. Edwin Bicknell in the chair. Twelve members 

 present. 



The Chairman exhibited a new binocular instrument by 

 Zentmayer, intermediate in size between the "grand" and 

 " hospital " stands. He stated that for some months he had 

 been using a Tolles binocular eye-piece and a fine Wenham 

 binocular made by Zentmayer, and had carefully compared 

 their performance. He found the Wenham best with objec- 

 tives of from 3 inches to ^ inch focal distance, and the 

 Tolles the best with f to T V objectives, and in stereoscopic 

 effect, the Tolles eye-piece far exceeds the Wenham arrange- 

 ment. 



Mr. A. H. Tuttle read a paper on a species of the genus 

 Uvella, Ehrenberg, a compound flagellate infusorian. 



December 20, 1871. 

 The President in the chair. Twenty-five persons present. 



The following paper was read : — 



Observations on the Development of Pholcus. 

 By James H. Emerton. Plate II. 



The spiders, from which the eggs were taken on which these ob- 

 servations were made, agree with the descriptions of Pholcus plia- 

 langioides Walck, and with the figure of that spider in Blackwall's 

 spiders of Great Britain and Ireland. They are very common about 

 Salem in cellars and dark buildings, but I have never seen one far 

 from houses. The embryology of this species has been studied by 

 Claparede and forms the principal part of his memoir on the develop- 

 ment of spiders. 1 



In July, 1871, several females were confined in glass cases and be- 



1 Recherches sur l'e volution des Araign^es. Utrecht, 1862. 



