168 



BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



r? 



two smaller colonies are of rounded outline, much flattened, but at- 

 tached by a somewhat narrowed base. 



Zooids easily visible through the test, very small (only 1.25 to 1.5 

 mm. long in the greatly contracted preserved state). Post-abdomen 

 rather short in all the individuals. Branchial aperture G-lobed, atrial 

 on a more or less produced tubular projection arising about the mid- 

 dle of the dorsal part of the thorax. It is sometimes obscurely 6- 

 lobed, in other cases net lobed at all. No atrial languet. 



Mantle with distinct but rather widely spaced 

 longitudinal muscle bands which are most con- 

 spicuous on the thorax. Numerous transverse 

 fibers, quite near together but not gathered into 

 bands, underlie the longitudinal bands on the 

 thorax. 



Tentacles, apparently about a dozen, of two 

 sizes, placed alternately. 

 Dorsal languets not demonstrated. 

 Branchial sac rather short with comparatively 

 few (probably about 6 or 7 rows of stigmata, 

 with about 14 in a row on each side. 



Stomach with about a dozen deep longitudinal 

 plications. 



Ovary consisting of a group of a few eggs 

 of different sizes in the anterior part of the 

 post-abdomen. Posterior to it the large pear-shaped or cuneate 

 testes form a double series along the common sperm duct. 



Localities : 



No. 21. Station D5109 (off Corrigidor Light, Jan. 15, 1908, 10 fathoms, 

 coral). One colony (Cat. No. 5903, U.S.N.M.) 



No. 75. Station D5555 (off Cabalian Point, Jolo, Sept. 18, 1909, 34 fathoms, 

 coarse sand). Two small colonies (Cat. No. 5902, U.S.N.M.). 



The above-described specimens agree so nearly with Sluiter's 

 (1909) description of A. depressum from latitude 7° 35' S., longi- 

 tude 117° 28.6' E., that there seems to be no reason for regarding 

 them as distinct, though Sluiter's specimen was from much deeper 

 water (521 meters). . 



LITERATURE. 

 Caullery, M. 



1908. Recherches sur les Synascidies du genre Colella et considerations 



sur la Faniille de Distomidae. Bull. Sci. France-Belgique, vol. 42 



pp. 1-59, text-figs. 1-16. 



Drasche, R. von. 



1882. Oxycorynia, eine neue Synascidien-Gattung. Verh. d. Zool.-Bot. 



Gesellsch. Wien, vol. 32, pp. 175-178, pi. 13. 

 18S4. Uber einige neue und weniger gekannte aussereuropiiische einfachc 

 Ascidien. Denkschr. Akad. Wiss. Wien, vol. 48, pp. 369-3S6, pis. 1- 



115 



Fig. 115. — Aplidium 

 dbpkessom slui- 

 teb. zooid. x 34. 



