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On a New Species op Metopidia. 

 By David Bryce. 



(Read April 21st, 1893). 



This new form has occurred in moderate numbers in a 

 " stock " jar containing a recent gathering of moss found 

 growing and partly immersed in running water in Epping 

 Forest. As, however, its presence in the moss gathered was 

 probably fortuitous, I do not regard it as an addition to the 

 moss fauna. 



Metopidia parvula, n. sp. 



Sp. Ch. Of minute size. Lorica ovate, much elevated, the 

 back rounded, the edges somewhat overhanging ; hind margin 

 rounded, ventral surface flat, foot and toes of unusual propor- 

 tions, the latter slender, acute and slightly flexible. 



As compared with M. pygmcea, which Mr. Gosse described 

 from a single Irish specimen, and whose occurrence has not, I 

 think, been again recorded, the most striking difference is in 

 the form of the toes, which in my specimens were very similar 

 to those of other species of the genus, whereas pygmcea is 

 stated to possess a " toe apparently single, small, acute." The 

 total length in each case being about the same, the new species 

 is apparently of much smaller bulk, as in it the toe accounts for 

 quite one-fourth of the total; and, further, although the lorica 

 is strongly arched, it is not so much so as shown in Mr. Gosse's 

 figure. The lorica alone measured as nearly as possible ^^J^th 

 of an inch in length, the greatest breadth being as 13 to 16. In 

 shape it is ovate, broadly excised in front, and rounded behind. 

 In young specimens the slightly overhanging margins of the 

 dorsal plate are a little turned inwards underneath, and there 

 is a distinct pinching in of the sides, at about the level of the 

 foot, producing an apparent obtuse pointing of the central 

 posterior margin. This disappears in older individuals, and the 

 hinder margin is seen to be entire and evenly rounded off, 



