EEPOET ON THE TUNIC ATA. 
45 
Imdcled. It is seen from the dorsal edge, and shows the mantle (m), the branchial sac, 
the prebranchial area in front bounded by the peripharyngeal bands, the oesophao-us, 
stomach (st) and intestine, and the two genital glands (o), which in these buds are always 
filled with ova of various sizes, some of them apparently mature or almost so. The 
genital glands iu the adult Aseidiozooid, on the contrary, show no ova, and appear to be 
merely testes. It is pretty certain, therefore, that protogpiy occurs here as in many 
other Compound Ascidians, and that each Aseidiozooid produces ova in its genital gland 
when young, and spermatozoa only when fully developed. In this wa}^ cross fertilisation 
is effected, the ova of the younger members of the colony being fertilised by the sperma- 
tozoa of the older ones. 
Botrjjlloides perspicuum, n. sp. (PI. I. figs. 4, 5 ; and PI. III. figs. 9-14). 
The Colony is lobed, but not very irregular in form ; it is rather thick. The surface is 
slightly uneven, but smooth. The general colour is a light brown, with a greyish-blue 
tinge in places. The anterior ends of the Ascidiozooids are light grey, but opaque. The 
edges of the colony, composed of test only, are a transparent grey, while the bodies of the 
Ascidiozooids cause the remainder of the colony to appear of a grey-brown colour with a 
slight tinge of purple. The common cloacal apertures are fairly numerous and conspicuous. 
The length of the larger colony is 4 cm., the greatest breadth 3 cm., and the 
average thickness about 4 mm. 
O 
The Ascidiozooids are elongated antero-posteriorly and placed at right angles to the 
upper surface of the colony. Each is about 2 mm. iu length and less than 1 mm. in its 
greatest breadth. The light coloured anterior end visible on the surface is about 
O’o mm. in diameter. 
The Test is firm and in some places rather thick. At the margins of the colony, 
where free from Ascidiozooids, it is transparent, and almost colourless or of a pale grey 
hue. Elsewhere it seems of a pale bluish-purple colour. The terminal knobs of the vessels 
are very conspicuous in most parts of the colony. They are numerous and of a jjurplish- 
brown colour. In som.e places, however, especially along the edges of the colony, they 
are of a light grey colour. The matrix of the test is homogeneous and compact ; it 
contains the usual small ovate and fusiform cells. Vessels are numerous and branch 
freely, especially near the surface and edges of the colony. The swollen terminations are 
very large, and usually more or less spherical in form ; they contain many j)igmented 
corpuscles of a brownish-purple colour. 
The Mantle is thin and very slightly muscular. It contains a number of large 
pigmented cells scattered through it. 
The Branchial Sac is large. The transverse vessels are of moderate lu’eadth and all 
