86 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



side. The individual figured has two gonads on each side, but the 

 number varies ; the largest specimen has three on the left and two on 

 the right side. The gonads themselves vary greatly in shape ; when 

 much elongated they are generally conspicuously constricted at one 

 or more points; the ovaries alone extending through the constricted 

 parts, while in the enlarged intervening segments small testes are also 

 contained. Though the state of the specimens renders the study of 

 the finer points of structure difficult, it seems not unlikely that the 

 ovary discharges by an orifice at the posterior end of the entire 

 gonad, while the testes in each segment probably discharge through 

 an orifice on a papilla on that segment. 



Collected by the Albatross expedition only at station D5623 (off 

 Makyan Island, 272 fathoms, fine sand and mud, Nov. 29, 1909), 

 where eight specimens (No. 102, Cat. No. 5978 U.S.N.M.) were 

 taken. These agree fairly well in most character with Sluiter's speci- 

 mens from several stations in the Malay region from depths rang- 

 ing between 204 and 472 meters. The Albatross specimens have more 

 vessels on some of the larger folds of the branchial sac, and the 

 writer could find at most five instead of six folds on a side. However, 

 considerable allowance must be macje for individual variation in 

 species of this genus, and the localities and depths lend support to 

 the belief that no mistake is made in including them in the same 

 species. As Sluiter (1904) has already pointed out, O. herdmani is 

 very closely allied to C. reeumbens Herdman, 1881, 1 although the 

 latter is from a distant locality (between the Cape of Good Hope and 

 Kerguelen Island) and much deeper water, 1,375 fathoms; but in 

 this connection it is worthy of mention that Wood-Mason and Alcock 

 (1891) record specimens which are very close to C. reeumbens, "if 

 not identical with it," from the Indian Ocean (station 110 of the 

 Indian Marine Survey steamer Investigator, 1,999 fathoms), indi- 

 cating a wide distribution for Herdman's species. With the informa- 

 tion available it would, however, seem premature to conclude that 

 the two species are identical. 



Family STYELIDAE Sluiter, 1895. 



[=TETHYII>\E Hartmeyer, 1008-1909, and Van Name. 1912, not Huntsman, 

 1912.] 



Genus STYELA Fleming, 1822. 



[=Tethyum Hartmeyer, 1DOS-1905), not Huntsman, 1912.] 



STYELA AREOLATA Heller. 



Plate 31, fig. 27. 



?1823. Ascidia plicata Lesueuk. Journ. Acad. Nat. Sci. Philadelphia, vol. 

 3, p. 5, pi. 3, fig. 6. 



iSee nerdman, 1S82, p. 107, pi. 11, figs. 1-7; pi. 12, figs. 1-7. 



