448 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.45. 



Neither these series nor those of other specimens counted indicate 

 anything distinctive in comparison with either Jiaustor or johnsoni; 

 and the same remark must be made concerning the other internal 

 systems— with the possible exception of the "liver." This structure 

 is not large in our animals and an extensive comparative study of 

 it might, perhaps, prove it to present constant differences. 



Type-locality.— Albatross 3088, lat. 44° 28' N.; long. 124° 25' 30" 

 W., 46 fathoms (close to the Oregon coast), September 3, 1889. 



T/y/je.— Cat. No. 5681, U.S.N.M. 



HALOCYNXmA AURANTIUM (Pallas). 



Ascidia aurantium Pallas, 1787, vol. 2% p. 240, pi. 7, fig. 38. 



Cynthia pyriformis Dall, 1872, p. 157. 



Cynthia superba Ritter, 1900, p. 590, pi. 18, fig. 1; pi. 19, figs. 16, 17, 18, and 20; 



pi. 20, fig. 19. 

 Cynthia deani Ritter, 1900, p. 592, pi. 18, figs. 2, 3; pi. 19, figs. 21, 22, 23. 

 Ealocynthia aurantium Hartmeyer, 1903, p. 195. 

 Salocynthia superba Oka, 1906, p. 41. 

 Pyura aurantium Hartmeter, 1909a, p. 1339. 

 Tethyum aurantium Huntsman, 1911, p. 136. 



For full synonymy see Hartmeyer, 1903, 



Table 7 gives the tabulated result of the examination of 26 

 specimens of the aurantium group of Halocynthia representing the 

 full extent of the geogi-aphic range of the group. Study of this table 

 shows that the specimens from the Pacific Ocean and Bering Sea 

 are undoubtedly separable from those of the Atlantic Ocean by the 

 number of gonads and probably also by the ratio of length to thick- 

 ness of the individual animals, and the character of the Sipines of the 

 test. 



