2 Tun. 
TUNIC AT A. 
Anajomy. 
Maurice (9) has given a most complete detailed account of the anatomy 
and histology of Fragaroides aurantiacum , a new Compound Ascidian 
closely allied to Fragarium elegans , Giard, which he found at Ville- 
franche. The colony owes its orange colour in part to the presence in 
great abundance of small parasitic A Igai ( Protococcus ), which are found 
in the test. As in many other Compound Ascidiaus, there is no colonial 
vascular system. The test cells act as phagocytes in removing the bodies 
of dead ascidiozooids. In the tailed larva the yoke is absorbed in the 
same way by the mesoblast cells (future blood corpuscles). The ascidio- 
zooids adhere to the test, not only at the branchial and atrial apei tures, 
but also along the lines of the longitudinal muscle bands, of which there 
are ten on each side. The atrial apertures open into ramified common 
cloacal cavities, and the atrial languets serve to keep these canals open. 
The branchial aperture has eight lobes. There are fourteen tentacles, of 
different sizes. Maurice considers the dorsal tubercle to be merely the 
orifice of the subneural gland. The branchial sac has thirteen to sixteen 
rows of stigmata on each side, with about thirty in each row. There are 
wide horizonal membranes and the usual dorsal languets. The transverse 
vessels of the branchial sac aro fused with the body wall, so as to divide 
the peribranchial cavity into a number of independent passages at the 
sides of the body, all communicating dorsally with the atrial cavity. There 
are muscles in the transverse vessels, as is the case in many other Com- 
pound as well as Simple Ascidians. An incubatory pouch is developed, as 
in Colellu and other forms, and the ova are introduced at its posterior end, 
so that the most advanced embryos are found anteriorly. The walls of the 
stomach are deeply channelled longitudinally. In connection with the 
nerve gangliou is found the posterior or visceral prolongation which is 
n >w being discovered in many species of Ascidians. Maurice is 
inclined to agree with Julin and others that the subneural gland is 
the homologue of the hypophysis cerebri, but he denies that it is either 
renal or mucous in function. The muscles are of a mesenchymatous 
nature, although Julin and E. van Beneden have shown that the Tunivata 
are enteroccelic. The post-abdomen contains the usual pericardiac and 
epicardiac tubes. In regard to the relations of these organs and the 
relations of the reproductive systems, Maurice supports Julin and Yan 
Beneden’s results. Most of the details in regard to the other parts of the 
body are similar to those already well-known in many other Compound 
Ascidians. 
Joliet (5) has left some unfinished studies in the anatomy of Pyrosoma 
giganteum. 
IIeudman (4, Appendix «) gives a description of the histology of the 
dorsal tubercle of a large unknown species of Asculia from Kerguelen 
Island. It consists of a large number of tubular glands, openiug by 
meaus of ciliated infundibula. It appears to represent the conjoined 
neural gland and dorsal tubercle of other A cidians in a very simple con- 
dition, and supports the view that these organs arc derived from a 
mucous gland. 
