MR. MACDONALD ON A NEW GENUS OF TUNICATA. 81 
The heart (fig. 3 d) lay in front of the stomach, extending 
into the interval between that organ and the cesophagus. 
The follicles of the testicle skirted the convexity of the intes- 
tinal curve, and immediately superficial to these were the sacculi 
of the ovarium. The ducts, however, converged from the hollow of 
the intestinal loop, and led forwards beside the rectum (fig. 3 ¢). 
Perophora is a pouch-bearer ; but the present genus, being a 
little pouch in itself, may be called Pera; and the species Huzleyi, 
after one who, above all English observers, has added most to our 
precise knowledge of the Twnicata. 
The original specimen from which this imperfect description 
was taken is now in the possession of Professor Huxley; and I 
may mention, in conclusion, that Professor Claparéde suggested to 
me the existence of a similar operculate condition of the test in 
the case of the so-called house of Appendicularia, in which, how- 
ever, I believe each aperture is furnished with a distinct valve. 
REFERENCES TO THE FIGURES. 
Fig. 1. Front view of the animal with the lid closed. 
Fig. 2. Side view of ditto (nat. size). 
Fig. 3. Posterior view magnified, with a portion of the test removed 
to show the internal organs. 
3 a. Mantle detached from the test below. 
zs 6. Stomach. 
55 ce. Intestine. 
a d. Heart. 
EN e. Testicular follicles. 
9 Jf. Ovarium. 
“A g. Ducts. 
Fig. 4. Front view magnified, with the operculum thrown open. 
3 a. Operculum. 
Br b. Body of the cell. 
‘3 c. Conjunctive membrane. 
a d. Branchial orifice with tentacula appearing. 
as e. Cloacal orifice. 
» J. Occlusor muscular fibres. 
LINN. PROC.—ZOOLOGY, VOL. VI. 6 
