26 University of California Publications in Zoology. ['Vol.4 



possesses but a single orifice. Nevertheless, unless the size of the 

 body is enormous, no considerable portion of the test can be 

 actually lackin"-, and it is surprising, to say the least, that the 

 same orifice should have been lost in both specimens. A large 

 expanse of test surrounds the orifice present, the branchial in 

 each case, and this it is that leads to the conclusion that the two 

 orifices are widely separated. If this be true, there would be a 

 distinct similarity here between the present species and Cory- 

 vascidia. 



The structure of the peduncle deserves more attention than 

 it gets in the diagnosis. I have labeled the core (pi. 2, fig. 2-4) 

 h.c, "body portion of the colunni." This I do not from evidence 

 furnished by its structure, that it is an extension of the body 

 wall. I have failed to discover either epithelium or muscle fibers 

 anywhere in the column. The whole core is a firm, gelatinous, 

 transparent material with spherical cells scattered uniformly, but 

 by no means numerously, through it. My chief reason for sup- 

 posing it to be in reality a portion of the body is that it is from 

 this that the roots, or hold-fasts take their origin (see figure). 

 Assuming these structures to be essentially the same as the 

 hold-fasts occurring in other rooted ascidians, e.g., Bhizomolgula 

 and Odacnemus, the mantle must have been implicated in their 

 production. There is no lumen, nor yet an axial strand of any 

 sort discoverable in the core. 



The outer sheath, fig. 24 tst., is with little doubt entirely tes- 

 ticular. Its nuitrix does not differ perceptibly from that of the 

 body, but it contains a far greater number and variety of cells 

 than does the body test. Many of these cells are spherical, but 

 many are long and narrow, almost to the extent of deserving to 

 be called fibrous. These extend in all directions and are without 

 regular arrangement. 



One might expect to find stiffening or supporting elements 

 of some sort in a stalk of the length of this, but none such exist 

 so far as I have observed. It may perhaps be supposed that the 

 organ serves as an anchor chain rather than as a supporting 

 column. 



The test of the body is noteworthy for its extreme transpar- 

 ency and the spareness of the cells contained in it. It is so 



