248 Miscellaneous. 



by Mr. Ed. Potts, of Philadelphia, in a specimen found in " a small 

 stream in the late Centennial grounds, Fairmont Park, Philadelphia " 

 {ih. '' about August 1880 "), which he then named "-S. todaspenna," 

 and subsequently " S. tenospenna'" {ih. p. 357), ending with "-Car- 

 terms tenosperma," its present name, has now been found in Southern 

 Russia and mid-Europe, as above stated. 



In the same communication also Prof. Petr has described and 

 illustrated, under the "provisional" name of "■ Ephjdatia bohe- 

 mica" another freshwater sponge, found at Kavasetice, in the same 

 district, wherein the statoblast presents an incipient condition of the 

 cirrous development characterizing Carterius, with a spiculation 

 which appears to me, from the illustrations, to be very like that of 

 his C. Stepanowii. 



Lastly, Mr. H. Mills, of Buffalo, in a letter dated 20th Nov. 1886, 

 sent me a specimen of Garterius from the Niagara River which he 

 considers allied to C. latitenta, Potts (Proc. Acad. Nat. Sci. Phil. 

 1882, July 10th, p. 12), wherein the expanded portion of this 

 development presents itself under the form of a cup, with even, 

 circular margin (that is, entirely without cirrous appendages), 

 whose bottom is pierced by the upright tubular part in the usual 

 way ; which " form " appears to prevail generally in the statoblasts 

 of this variety. 



On some Optical Properties of the Peristome of Mosses. 

 By M. J. Amann. 



The author describes some curious properties of the peristome of 

 mosses when under polarized light. These properties, which have 

 not been described up to the present time, deserve a closer study. 

 According to M. Amann's observations, sometimes the outer layer 

 of the peristome (exostome), sometimes the inner layer (endostome) 

 rotates the plane of polarization and exhibits, when a thin plate of 

 mica or of selenite is interposed, very brilliant colours, varying with 

 the position of the two Nicols relatively to each other. This action 

 of the peristome on polarized light varies from one family or genus 

 to another. It is occasionally almost nil (Pottiacea?, Weissiea?) ; 

 feeble in the Grimmiacea^ and Dicranacese ; strong in the Mniaceae 

 and Hypnaceae. Thei-e appears to exist a curious relation between 

 these optical properties and the amount of tannin contained in the 

 membranes : thus, those richest in tannin are the most active ; the 

 endostome of Camptothecium luteseens affords a particularly good 

 illustration in this respect. — Bibliotheque Universelle, Archives des 

 Sciences, Dec. 15, 1886, p. 585. 



