THE ASCIDIANS 25 1 



row, elliptical area with no folds ; the folds in the immediate vicinity 

 of this disposed at an angle rather than parallel to it. 



Reproductive organs. — Many embryos present in the atrial cham- 

 bers of many of the zooids, but the sexual glands unusually inconspic- 

 uous ; in many zooids not recognizable at all without particular atten- 

 tion. Ovary situated far behind the intestinal loop, though in some 

 cases, apparently only a short distance behind it. 



This Amaroiichan bears a strong superficial resemblance to an 

 undescribed species of Synoictiin from the coast of California, and 

 was at first supposed to be this or a closely allied form, but more care- 

 ful study removed all doubt about the genus to which it belongs. 

 As mentioned in the diagnosis, and shown by the figures, there appears 

 at first sight to be no grouping of the zooids into systems ; and the true 

 state of things was ascertained only after this point had received special 

 attention. It would seem that the common cloacal orifice becomes 

 wholly obliterated in most of the colonies, the zooids then becoming 

 as vmiformly distributed as they are in genera like Disto7tia. in which 

 each atrial siphon opens by itself. What the method of exit of the 

 excreta is in these conditions, I am not sure, as I have not been able to 

 detect any single orifices. The long atrial languets may be seen 

 embedded in the test, and apparently the siphons to which they belong 

 have, in most cases, no openings to the surface of the colony. In a few 

 colonies, particularly those of small size, an occasional rather large and 

 conspicuous common cloacal orifice may be seen. 



The species is more closely related to Amarouci'um proliferufn M. 

 Edw. than to any other, particularly if this species is held, as Lahille 

 believes it should be, to include several forms that have been described 

 by other authors as separate species. From all the varieties of prolif- 

 erum the present form differs, however, in the absence of composite or 

 ramified colonies characteristic of proliferzan^ in the smaller size of 

 the masses, the less distinct systems of the zooids, and the greater 

 regularity of the folds of the stomach wall. The specific name refers 

 to the unusual transparency of the test. 



Found at Orca, Prince William Sound, Alaska, on reefs at low tide. 

 Collected June 26, 1899. About one hundred colonies in the collec- 

 tion. 



AMAROUCIUM COEI sp. nov. 



(PI. XXIX, figs. 31 and 32.) 



General characters of the colony. — In large pear-shaped masses, 



many of them loosely joined together by their narrow bases. The 



masses, as a rule, very regular in form, the expanded end nearly cir- 



