8 Universiiy of California Publications in Zoology. ["Vol. 4 



oides (Sluiter '04) than to any other species. But of course the 

 characters of the dorsal lamina and branchial membrane put 

 Eiigyra out of consideration for our species. 



Finally turning to the troublesome orifices, the recently estab- 

 lished Astropera (Pizon '98), possessing as it does a gonad on 

 each side of the body, holds out at first sight some promise of fur- 

 nishing a lodging place for our species. But the absence of the 

 peculiar petaloid lobes of Astropera, taken with differences in the 

 number of branchial folds, and in the position of the left gonad 

 relative to the intestine, to say nothing of the absence of the spic- 

 ules in Astropera, make it out of the question to seriously consider 

 uniting our species to Pizon 's genus. 



I conclude, then, that Halomolgula ovoidia is a representative 

 of a group of Molgulids that holds some such relation to Molgula 

 as that held by RJtabdocyntJna to Cynthia. When, however, one 

 searches through the known species of the family Molgulidae for 

 a species that might have been the parent of H. ovoidia, not much 

 success is met with. 



In view of the fact, noted by Sluiter '04, that the species of 

 RJtabdocyntltia are, most of them, inhabitants of seas in which 

 coral reefs abound, it is worth while to point out that such is not 

 the case Math H. ovoidia. There are very few corals or other cal- 

 cium carbonate-producing species in the region to which this ani- 

 mal belongs. The collection contains about one hundred and fifty 

 specimens. 



Station 4425, 21.8 miles S. 7°E. point of San Nicholas Island, 

 1000 to 1100 fathoms, bottom green mud and fine sand, and glob- 

 igerina, associated with much hexactinelid sponge. April 13, 

 1904. 



Molgula regularis, n. sp. 



PI. 1, figs. 7 and 8. 



Superficial Characters. — Ellipsoid, very regular in outline, 

 surface entirelv covered with foraminiferous shells and sand par- 

 ticles, which cling closely to the great number of filiform processes 

 of the test. No definite area of attachment, though a thin mem- 

 brane-like substance loosely adhering to one side of some of the 

 specimens may mark the place of contact with the substratum on 



