326 MR. G. 8S. WEST ON SOME BRITISH 
erey endoplasm enveloped in a larger mass of clear transparent 
ectoplasm. 
Length of shell 48-55  ; diameter of shell 36-40 » ; diameter 
of mouth 15-17 p. 
This interesting Rhizopod was abundant among various Alge 
and Isoétes, in the shallow water at the margins of Llyn-y-cwm- 
ffynon, Glyder Fawr, N. Wales. 
The structureless shell at first reminds one of Hyalosphenia, 
but, apart from the entirely different nature of the animal, the | 
shell is at once distinguished from shells of that genus by its 
circular cross-section and circular mouth. It is a thin, trans- 
parent, chitinoid shell, generally somewhat obliquely ovoidal 
(or ellipsoidal), and possesses a slightly expanded, minutely bell- 
shaped mouth at the narrower or ventral pole. The shell is 
quite firm and rigid, and the body-protoplasm of the animal 
completely fills it, fitting closely to the inner surface. 
The nucleus, which, as compared with that of other lobose 
Rhizopods, is exceedingly large, is situated towards the extreme 
dorsal pole of the shell, and exhibits a finely punctate appearance. 
The body-protoplasm is of a dull grey colour, and is filled with 
eranules of variable magnitude, more especially in the region 
immediately ventral to the nucleus. Various food-particles in 
different stages of digestion are noticeable in almost every 
individual, the animals feeding largely on unicellular Palmellacez. 
The method of feeding is quite normal. 
One of the most remarkable features of Leptochlamys is the 
extraordinary pseudopodium. On the protrusion of the pseudo- 
podium the animal first exudes from the mouth of the shell a 
more or less globular mass of ectoplasm, which is transparent 
and very byaline in appearance. ‘This is followed by an exuda- 
tion of slightly darker-coloured, homogeneous endoplasm. The 
pseudopodium is quite a large mass, ever changing its shape, 
but never at any time becoming divided into two pseudopodia. 
At most, it becomes retuse at the broad, distal end, and at 
all times there is a well-marked separation into ectoplasm and 
endoplasm. 
No vacuoles (contractile or otherwise) were observed in any of 
the animals, and so far as I could ascertain they were absent. 
The genus is undoubtedly nearest to Cryptodifflugia, Penard 
(Gn Mém. Soc. Phys. et d’Hist. Nat. Genéve, tom. xxxi. no. 2, 
1890, p. 168, t. vu, ff. 95-107), but is readily distinguished by 
