1907] Fitter. California Coast Ascidians. 1 



The gonads are practically of the same size on the two sides 

 of the body. Only in the larger individuals are they fully devel- 

 oped. In these the axial part of the sausage-shaped mass is read- 

 ily seen to be the ovary, and here many of the ova are relatively 

 large. Along this ovarian axis, for its entire length, the pear- 

 shaped testis lobes are disposed on both sides. These lobes are 

 uniform in size and shape, and are placed with their larger ends 

 directed away from the axis. Both gonads converge toward the 

 atrial chamber so that their orifices, as well as the esophageal open- 

 ing and the anus are near together, and all are near the atrial 

 siphon. 



The character, which more than any other, has compelled me to 

 establish a new genus for this species is the calcareous spicules in 

 the test. Starting from this feature, and considering along with 

 it the slight extent to which the stigmata are curved, I have tried 

 to force the species into the genus Rliabdocyntliia, Herdman. But 

 even relying on the spicules alone, the fact that in our present 

 species they are confined to the test, whereas in Rhabdocynthia 

 they are present in other tissues, as the mantel, branchial vessels, 

 etc., makes a quite sharp contrast between the two types. There 

 is, however, an undoubted tendency toward a curvature of the 

 stigmata in H. ovoidia. When this is coupled with the well- 

 marked infundibula of the branchial sac it becomes obvious that 

 Rhabdocijntliia will not receive our species, indeed that it must be 

 associated with the Molgulas rather than with the Cynthias. 



After the spicules the characters most seriously in the way of 

 assigning the species to any recognized genus are the two orifices, 

 the number of branchial folds, the position of the gonad of the 

 left side, and probably the structure of the renal organ. 



No Molgulid, so far as I am aware, possesses more than seven 

 branchial folds on each side. Since, however, the genus Molgula 

 is allowed six and seven folds (and five if, as Hartmeyer '03 be- 

 lieves, Pera should not be separated off) , I should not be disposed 

 to permit even the nine folds of H. ovoidia to stand in the way of 

 assigning it to an old genus were there no other difficulties in the 

 way. 



As regards the relation of the intestinal tract and gonads, H. 

 ovoidia has greater resemblance apparently to Eugyra molgul- 



