116 THE ROTIFERA. 
It is somewhat slow of motion. The medial line of the venter is a salient angle; and 
this has a curious effect as the creature revolves.—P.H.G.] 
Length. Of lorica, ;4, inch. Habitat. Pond at Lower Clapton (P.H.G.). 
P. suncata, Hudson. 
(Pl. XXVIL fig. 2.) 
Pompholyx sulcata  . 5 A Hudson, J. Roy. Micr. Soc. 1885, p. 613, pl. xii. figs. 7, 8. 
SP. CH. Lorica entire, divided into four convex lobes, by four longitudinal 
furrows. 
The lorica of this species is very unlike that of Mr. Gosse’s P. complanata. In the 
latter the dorsal and ventral surfaces are so compressed that they are slightly concave, 
while in the former both these surfaces are sharply convex, and so are the connecting 
lateral surfaces. A transverse section, consequently, consists of four segments of circles, 
as shown in fig. 2b. It is easy to obtain this view, as well as a good sight of the corona 
with its two wheels and red eyes, for the animal is fond of swimming upright close to 
the cover-glass, or of exploring the bottom of the live-box, head downwards. I had little 
opportunity for studying the creature, but I noticed that the lorica had an aperture in 
its lower, pointed, and somewhat curved extremity. 
I am indebted to Mr. Bolton for this pretty little Rotiferon, which he discovered in 
company with Conochilus dosswarius in the summer of 1884. 
[A curious habit which this genus has in common with Brachionus is that of carrying 
the eggs, after they are successively discharged, until the young burst the shell. These 
are nearly circular (absolutely so as often presented to the eye), very large in propor- 
tion to the animal, each connected by a highly elastic thread to the hindmost part of 
the lorica, between its two terminal points. This thread can be lengthened or shortened 
at the will of the animal, and this in a surprising manner ; for by very careful observa- 
tion I perceived that, in elongating, the slender elastic thread was actually projected, the 
ege of course being inert, and nothing pulling or even touching it. And to a surprising 
extent; for I have seen the thread to equal in length the longer diameter of the egg. 
The front edge of the lorica rises to a rounded projection dorsally, and two of less 
elevation laterally ; these latter appear to be separated by a shallow sinus pectorally. 
The mastax is small, the trophi formed on the pattern seen in Pterodina, an incus with 
small fulerwm and quadrantiform rami, and with obsolescent mallet. I have seen re- 
traction of the anterior parts to such an extent that the foot of the imcus was very 
nearly at the bottom of the visceral cavity.—P.H.G.] 
Length, ;}, inch. Habitat. Near Birmingham (T.B.): rare. 
Family XVII. BRACHIONIDA. 
[Lorica box-like, open at each end, generally armed with anterior and posterior 
spines ; foot long, excessively flexible, wholly retractile, wrinkled, ending in two toes. 
Genus BRACHIONUS, Ehrenberg. 
GEN. CH. Lorica without elevated ridges, gibbous both dorsally and ventrally ; 
foot very flexible, uniformly wrinkled, without articulation, toes very small. Lacustrine 
and marine. 
This genus contains Rotifera mostly of large size and of showy appearance, being 
inclosed in glassy shells of regular outline, adorned with symmetrical projections, and 
always presenting a broad surface to observation. They have been favourites with 
observers from the dawn of microscopy; and they are still. Fortunately most of the 
species are common and easily accessible. The form of the foot is peculiar; it is a long 
