W. G. Van Name — Bermuda Ascidians. 353 



The zooids are rather large and stout. A fair sized specimen 

 measures 2.3 mm long without the post-abdomen, which may itself 

 reach 4 or 5 mm in length, though in most individuals it is much 

 shorter. In color they vary from orange to bright vermillion red in 

 life, but gradually fade to yellow in preservation. The color is dif- 

 fused through most of the tissues, but in very red individuals the 

 mantle of the thorax contains an especially large amount of pig- 

 ment. The mantle, especially near the anterior ends of the thorax, 

 abdomen and post-abdomen, is often studded with rounded cells, 

 much larger than the ordinary epithelial cells. 



Usually there are six lobes to the branchial orifice, but some indi- 

 viduals have more. There is a fairly large atrial languet placed a 

 little anterior to the orifice, which is itself provided with distinct 

 though very short lobes. The usual number of rows of stigmata 

 appears to be about eighteen, with more than a dozen in a row on 

 each side. They are small and round and placed rather far apart. 

 The transverse vessels are very muscular. The tentacles are small 

 and difficult to count. 



The presence and arrangement of folds or plications in the wall of 

 the stomach have been made the chief characters by which the 

 genera of this family are distinguished. In the present species, how- 

 ever, it is clear that great importance should not be attributed to 

 them. Usually the stomach of this form has distinct longitudinal 

 folds, but often there are transverse folds also over more or less of 

 the surface, or the transverse folds may even predominate and 

 become the principal ones, exceeding the longitudinal folds in prom- 

 inence. Some individuals show, on some parts of the surface of the 

 stomach, an areolated condition not far removed from that which 

 is typical of the genus Morchellhim Giard. Others, again, appar- 

 ently have the stomach entirely smooth-walled in its natural condi- 

 tion, but in this species the stomach-wall is very thin and liable to 

 become folded by the contraction of the animal incident to preserva- 

 tion, and its original condition is not always easy to determine. 



In another species of this genus, A. constellation Verrill, from the 

 New England coast, which normally has a longitudinally folded 

 stomach, I have also observed variations from the usual condition, 

 though not to such a great extent. 



Many specimens of this species were collected, both in 1898 and 

 1901. It was found most abundantly on corals in Harrington Sound, 

 in water of moderate depth, and evidently grows better in such situa- 



Trans. Conn. Acad., Vol. XI. 23 February, 1902. 



