NOTES ON RETICULARIAN RHIZOPODA. 51 



ously combined. Polythalamous forms spiral, crozier-shaped, 

 acervuline or linear in contour. Texture more or less roughly 

 arenaceous. 



.Placopsilina vesicularts, n. sp. PI. V, fig. 2. 



Characters. — Test, irregular in shape and size, spreading 

 in indefinite patches over stones; usually composed of several 

 convex chambers, either connected by short stoloniferous 

 passages or crowded one against the other ; margins rounded 

 or lobulate, with simple or forked tubular extensions which 

 form the pseudopodial apertures. 



The drawing (PL V, fig. 2), scarcely needs verbal 

 comment beyond the descriptive characters above detailed. 

 Placopsilina vesicularis, is by no means a common species. 

 In one of the " Porcupine" dredgings from the North Atlantic 

 (1215 fathoms), sent to me by Sir Wyville Thomson, a 

 number of the little stones brought up had adherent 

 specimens in various stages of development, and from one of 

 these the figure is taken. 



Geims — REOPHAX, de MontforL 



General characters. — Test free, uniserial ; consisting of a 

 single flask-shaped chamber, or of a number of segments 

 joined end to end in a straight, curved, or irregular line. 

 Texture arenaceous, more or less rough externally ; chamber 

 cavities simple, non-labyrinthic. Aperture terminal, simple, 



E.EOPHAX DIFFLUGTFORMIS, W. Sp. PI. IV, fig. 3, a, h. 



Characters. — Test free, consisting of a single, undivided, 

 rounded, or oval chamber, with produced neck. Wall thin, 

 arenaceous ; the constituent particles of sand neatly joined, 

 and presenting a nearly smooth exterior. Length -r-^ inch 

 (0-5 millim.). 



Had this little organism been found in fresh or brackish 

 water, or even in shore-pools, it would, without doubt, have 

 been assigned to the DiffiugicE ; and it is perhaps an assump- 

 tion rather than an ascertained fact that Rhizopoda with 

 lobulate pseudopodia have no home in the deep sea. Neverthe- 

 less, as the test bears the same sort of relation to the monili- 

 form LitaoliB as that of Lagena does to the Nodosarice, 

 there is a natural place for it in the Reticularian series. 



There is nothing, either in the specimens themselves or in 

 the forms with which they are associated, to suggest that they 

 are other than mature representatives of a species ; but the 



