Gh THE ROTIFERA. 
protrusile ; alimentary canal very large, projected behind and above the mastax, always 
filled with green matter. 
This is an animal of no inconsiderable size, which has the technical characters of 
Diglena, but has little affinity with that genus, in structure or manners. My first ac- 
quaintance with it was in October 1849. A filamentous plant, growing in a pan sunk in 
my own garden, was thickly covered with a floccose matter, inhabited by numbers of 
Stentor polymorphus. Among them were specimens of this Diglena (?). In January 
1851, I again found it in the same water, and on a subsequent occasion; but I have 
never met with it since. 
The form is gracefully swelling and vase-like, not at all resembling a Diglena in 
appearance ; it has much the aspect of being loricate, but it is not. Two eyes are placed 
at the extreme front ; small, so close together as to be readily mistaken for one, brilliantly 
crimson. The transparent mastax, im situ, shows a pair of incurved strong pincers, 
whose approaching tips are two-toothed. These can be extended from the front for 
half their length, and seem to be a formidable instrument for seizing prey. These are, 
no doubt, the rami of an incus. What appears remarkable is that a great saccular lobe 
of the stomach runs up behind the mastax into the occiput, and divides into two lobules. 
The whole alimentary canal, with these lobes, was, in every example, uniformly filled 
with round green granules, the exact similarity of which to the component granules of 
the Stentors and the Loxodes, which abounded in the same water (together with various 
species of Huglena), suggested that the normal food of the Rotiferon may consist of the 
juices of these Polygastrica, especially as its formidable forceps seems to indicate car- 
nivorous propensities. The long straight rod-like toes are now and then turned up, so 
as to incline over the back; occasionally their tips are crossed.—P.H.G.] 
Length, ;3, inch. Habitat. A garden-pan near London (P.H.G.): rare. 

Genus DISTEMMA, Ehrenberg. 
(GEN. CH. Body more or less cylindric, long, slender before, swollen behind, ver- 
satile ; two cervical eyes ; front furnished with a fleshy proboscis ; toes two, furcate. 
This somewhat obscure genus Ehrenberg constitutes on four species. These, how- 
ever, must be reduced to two: for D. setigerwm clearly belongs to the family Rattulide ; 
and D. marinum is one of the Loricata. The others I have not met with. But I 
enumerate three species, apparently undescribed, which seem to come into the genus. 
In aspect and manners they closely resemble Diglena, especially in their long, lithe, 
versatile forms, generally swollen behind ; in the presence of soft tentacular appendages 
to the front; in the forcipate form and protrusile character of their trophi; and in their 
fierce raptorial habits. The species inhabit the sea and fresh waters.—P.H.G.] 
D. rapror, Gosse, sp. nov. 
(Pl. XIX. fig. 1.) 
[SP. CH. Body long, gibbous behind, very changeable ; front with a long projectile 
lip ; foot short; toes small, slender, decurved. Marine. 
The lithe flexible form is usually lengthened, slender in the middle, becoming high 
behind, its outline descending in an abrupt curve to the very small foot. This is armed 
with two toes, whose thickness tapers abruptly at the middle (fig. 1c). It is near 
D. forcipatwm, but is distinguished by this peculiarity of the toes, and by their curvature. 
And it is marine. The head is rounded, the front produced into three fleshy ciliate 
points, and a conical projection on each side, The central point is probably the tip of a 
curious fleshy process, which is now and then rapidly pushed out and in (figs. 1, 1a), quite 
straight, thus differing from the proboscis of Diglena. The lateral projections, when this 
