PLATE II. 
ai.n. Nen'es leaving posterior end of 
ganglion. 
b.c. Blood-corpuscle. 
br. Branchial aperture. 
d. 1. Dorsal lamina. 
d.t. Dorsal tubercle. 
cn. Endostyle. 
g. Reproductive organs. 
gl.d. Duct from neurd gland. 
i. Intestine. 
Botrylloides tyreum^ n, sp. 
i.l. Internal longitudinal bar of bran- 
chial sac. 
l.v. Fine longitudinal vessels of bran- 
chial sac. 
m. Mantle. 
m. b. Muscle band in mantle. 
n. g. Nerve ganglion. 
0 . Ovary. 
ce. (Esophagus. 
p.p. Peripharyngeal band. 
r. Rectum. 
sg. Stigmata of branchial sac. 
sg.c. Ciliated cells, bounding stigmata 
of branchial sac. 
st. Stomach. 
t.c. Test cells. 
t.Tc. Terminal bulb on vessel in test. 
t.m. Test matrix. 
tr. Transverse vessel of branchial sac. 
tn, til'. Tentacles. 
V. Vessel in test. 
z. Prebranchial zone. 
Fig. 1. Part of the test showing the system of vessels and terminal knobs ; magnified 
(S., 1 inch). 
Fig. 2. A small portion of the test, more highly magnified, showing a terminal knob 
filled with blood-corpuscles (S., ^ inch). 
Fig. 3, Part of the mantle, showing the muscle bands, their nuclei and other details ; 
highly magnified (S., ^ inch). 
Fig. 4. Part of the branchial sac, seen from the inside ; magnified (S., 1 inch). 
Fig. 5. A small portion of the branchial sac, from the outside ; more highly magnified 
(S., ^ inch). 
Fig. G. The anterior extremity of the endostyle and neighbouring parts; magnified 
(S., 1 inch). 
Fig. 7. An Ascidiozooid, seen from the ventral part of the right side f magnified (S., 1 
inch). 
Fig. 8. The anterior extremity of an Ascidiozooid, seen from the inside, showing the 
dorsal lamina, prebranchial zone, tentacles, &c. ; magnified (S., 1 inch). 
Fig. 9. The dorsal tubercle, nerve ganglion, and neighbouring parts, seen from the 
outside ; highly magnified (S., inch). 
Fig. 10. The genital gland of a full grown Ascidiozooid; magnified (S., 1 inch). 
I'ig. 11. A young Ascidiozooid, not yet fully developed, showing the two large ovaries ; 
highly magnified (S., ^ inch). 
* Nanicfl J’otrylloideg purpureum on plate. 
* This figure waa not reversed on the stone, and consequently the alimentary canal appears upon the wrong side of 
the branchial sac. 
