480 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.45. 



It is quite impossible to separate the individuals from one another, 

 the fusion being almost as complete as though the mass were one of 

 compound ascidians. 



The internal organs are typically grossularian, considering the 

 range of variation of the species that has been pointed out, particu- 

 larly by Herdman, 1882, Lacaze-Duthiers and Delage, 1893, and 

 Hartmeyer, 1903. The only possible exceptions to this statement 

 are these: The fold projecting into the intestine, or typhlosole, is very 

 prominent in the specimens at hand, it extending nearly the whole 

 length of the gut and in places nearly dividing the lumen into two ; the 

 pyloric pouch of the stomach is relatively short in the individuals 

 examined and seems not to reach across the intestinal loop to the 

 opposite limb of the intestine, as it is figured as doing in grossularia; 

 and finally, the lobes of the testes in my specimens are more numerous 

 and voluminous relative to the ovary than seems to be the case with 

 individuals of grossularia heretofore described. 



Taken all in aU, I conclude that, while it is possible it is not proba- 

 ble that the study of more ample material will find it necessary to set 

 off the Bering Sea members of the Styelopsis group from grossularia, 

 and that, consequently, the already very wide range of this species 

 must be extended by several thousand miles. 



A single mass of specimens from St. Paul Island, Bering Sea, 

 taken in July, 1897. 



DENDRODOA TUBERCULATA Ritter. 



Plate 34, fig. 27 



Dendrodoa tuberculata Ritter, 1899, p. 512, figs. 1-5. — Hartmeyer, 1903, p. 243, pi. 5, 



fig. 9; 1909a, p. 1362. 



The genus Dendrodoa is one of those groups of organisms which the 

 more it is studied (up to some limit not yet ascertamed in this case) 

 the more dubious become the boundary lines of the subgroups into 

 which it may be divided. When I described the two species, tube?'- 

 culata and suhpedunculata, in 1899 it seemed that the delimitations, 

 not only between these two species but also between these and any 

 of the previously known species, was satisfactorily definite. Since 

 then, however, the studies of Hartmeyer and now my own have 

 brought out strikingly the great variability of the animals, and so 

 demonstrated that the subgroup boundaries can be made out only 

 by the most searching examination of a great quantity of carefully 

 collected well-preserved material representing the whole geographic 

 range of the genus. 



