NOTOMMATAD AS. 53 
Tam not quite clear whether I ought to name this form. But, assuming that the 
cluster of unequal-sized and irregular-shaped red specks, resembling the fragments of 
crushed rubies, at the very front of the head, represents two frontal eyes, I place it in 
this genus, especially as the trophi appear to agree with those of the slenderer Diglene, 
and there is much similarity to them in general contour and conformation. 
Its shape is long, thin, and nearly parallel-sided, viewed dorsally (fig. 5), abruptly 
narrowed to a very slender foot, and long, thin, acute, decurved toes. Laterally (fig. 5a), 
the lumbar region is gibbous without any marked fold. The eyes, resembling broken 
fragments, as said, are placed at the very front ; and are conspicuous, even in the swift 
shootings of the animal. The front descends to a blunt angle, which may be the 
anterior point of a prone ciliated face. I could discern no fleshy hook. I did not detect 
the brain; but behind the mastax were two opaque globules, which seemed not to be 
eyes, but were possibly chalk-masses, smaller, and more shapely, than usual. A very 
long alimentary canal reached far down the cavity, well filled with food of various tints, 
accumulated in many dark nodules, which imparted to the animal in its movements a 
very peculiar spotted appearance. Most of the internal structure is as yet undefined. 
This is one sample of the very rich harvest of species that I reaped out of a small 
bottle procured for me from Sandhurst Wood pool, by Dr. Collins, in June 1855. 
Though I had the specimen under my eye for an hour or more, I could scarcely, in all 
that time, find it still long enough to permit me to turn to the paper, in order to delineate 
it; and if I did, I was almost sure to lose it out of the field, to find it again with difti- 
culty. It is swift and headlong in its course, shooting through the free water rather 
than swimming, and only now and then entering a cloud of floccose sediment, to push, 
with persevering violence, a way through it. 
Only this single example has been subjected to examination.—P.H.G.] 
Length, ;1,; inch. Habitat. Sandhurst, Berks (P.H.G.). 
D. catenuina, Hhrenberg. 
(Pl. XIX. fig. 10.) 
Diglena catellina = : Ehrenberg, Die Infus. 1838, p. 444, Taf. lv. fig. 3. 
[SP. CH. Body cylindric, short, abruptly truncate at each end ; toes short, straight 
acute, projected from the ventral side, at a right-angle to the body-azis. 
This plump, sturdy little creature occurred among my earliest researches in the 
summer of 1849. It is a true Diglena, yet is very dissimilar to its fellows, replacing 
their long, lithe slenderness by a short thick body, having strong skin-folds, often quite 
abruptly truncate before and behind. Now and then, indeed, a bluff rounded head is 
pushed out, carrying two eye-peints at its front, and a ciliated face, hardly prone. 
From the broad square stern, a small foot projects at the lower margin, and two small, 
slender, acute toes, pomting downward, serve the creature for support and for locomo- 
tion. The internal organs are little noteworthy. There is a large occipital brain, and 
an enormous mastax, of which the jaws are normal. 
Ehrenberg describes this tiny species as both marine and lacustrine. I have found 
many specimens from tide-pools in the Tay estuary, collected by Mr. Hood.—P.H.G.] 
Length, 51, to ;}; inch. Habitat. A garden near London; a pond at Snaresbrook 
(P.H.G.); Sandhurst (Dr. Collins); marine tide-pools in the Firth of Tay (P.H.G.). 

DiIGuLENA (?) BIRAPHIS, Gosse. 
(Pl. XIX. fig. 3.) 
Diglena (2) biraphis < : Gosse, Ann. Nat. Hist. vol. viii. 1851, p. 200. 
[SP. CH. Body oblong, the head and abdomen gently swelling ; toes long, slender, 
straight, and perfectly even in thickness ; eyes placed close together frontally ; jaws 
