BRACHIONIDA. 117 
and thick muscular tube, very transparent, covered with minute and close wrinkles, full 
of muscles, which admit of rapid protrusion and retraction, and of motion in all diree- 
tions, with amazing flexibility (so that I have actually seen it tied in what, for the 
moment, looked like a knot!). The toes,—so small and apparently feeble,—have con- 
siderable power of grasping. They are sometimes used as a pivot on which the animal 
revolves. The mutual relations of the sexes are very distinct ; as I have shown in detail 
in my Memoir “‘On the Diccious Character &c.” (Phil. Trans. 1856). The female 
carries the excluded eggs attached to her body till they are hatched. 
The distinction of the species rests mainly on the number, dimensions, and relations 
of the spines. Yet recent observations on B. pala throw doubt on the validity of such 
characters.—P.H.G.] 
B. pata, Ehrenberg. 
(Pl. XXVII. fig. 3; and Pl. XXVIII. fig. 3.) 
Brachionus pala . 5 a 3 Ehrenberg, Die Infus. 1838, p. 511, Taf. Ixiii. fig. 1. 
s amphiceros F ‘. 5 Die Infus. 1838, p. 511, Taf. Ixiii. fig. 2. 
06 polyacanthus . : Cohn, Sieb. w. Koll. Zeits. Bd. xii. 1863, Taf. xxii. fig. 4. 
i amphiceros . “ Plate, Jenaisch. Zeits. f. Natur. 1885, p. 65, Taf. ii. figs. 22-24. 
SP. CH. Lorica thin, smooth, transparent ; with four, long, sharp, occipital spines. 
B. pala has a colourless, smooth and transparent lorica, armed with four long spines 
in front, but unarmed and rounded off behind. The lorica is flexible, and generally 
dragged-in a little on either side, round the attachments of the long dorsal muscles. 
The opening for the foot is a mere slit, through a pap-like protuberance at the end of 
the lorica; and its sides can be brought close together when the foot is withdrawn. The 
animal’s internal organization is very ike that of B. rwbens, which has already been so 
fully described in Chapter I. that, beyond a reference to Pl. A, vol. i., and Pl. XX VII. 
fig. 3, only a few points require notice. The mastax is very large ; and so are the trans- 
parent vesicles which are seated on it on the ventral side, and may possibly be salivary 
glands. By transmitted light they show only two curved lines (their outer bounding 
walls) rising from the mastax to the head. The gastrie glands are stalked, as in B. 
rubens, but the stalks are generally hidden behind the broad triangular ends of the glands.! 
The vascular system is very conspicuous, and the five tags on each side can be readily 
found. I once obtained an admirable view of the top of a vibratile tag, which was 
pointing up the microscope. It was not at all like that of Huchlanis dilatata given by 
Dr. Plate, and taken from the same point of view. Dr. Plate figures the summit of the 
tag as an oval with pointed ends. I found that of the lowest tag of B. pala to be a thin 
straight edge, like that of a chisel. If there be an aperture there, it must be extremely 
narrow. As the animal moyed, the tag turned too, so as to present also the two charac- 
teristic appearances given in Pl. XIII. fig. 30. 
Along with the undoubted specimens of B. pala were a good many of what appeared 
to be Ehrenberg’s B. amphiceros, with two short thorn-like spines on the lumbar 
regions, and two others still smaller, one on each pap-like protuberance by the foot 
(fig. 8c). Ehrenberg says that B. amphiceros differs from B. pala in its smaller size, in 
having no coronal styles, in having four sharp posterior spines on the loriea, in lacking 
side muscles in front, and in having four vibratile tags stead of three. Moreover he 
says that he could not find a dorsal antenna. Now I carefully examined these speci- 
mens with four posterior spines, and found them to be of the same size as B. pala, with 
styles on the corona, with side muscles in front, and possessing a large dorsal antenna. 
In fact they were the exact counterparts of pala. I may add, too, that both those which 
had, and those which had not posterior spines, showed, under favourable circumstances, 
five vibratile tags on each side. Nor is this all: for I found some specimens with two 
‘ The lower ends of these glands are tied to threads, which are attached to the lorica just above the 
heads of the lateral antennm, and at their other extremities to the stomach. Mr. Gosse discovered 
and drew this arrangement, as well as the lateral antenna themselves, in 1850. 
