ASCIDIANS OF THE PHILIPPINES — VAN NAME. 161 



average. Attachment only by a small area on the central part of the 

 lower surface, the marginal portions of the colony being free. The 

 general form of the colony is thus that of a flattened saucer of irregu- 

 lar outline. Surface of colony smooth and clean ; test firm and tough, 

 of a greenish white color; the tissues of the zooids are of a deeper 

 greenish color, so that they show through the test quite distinctively. 

 Superficial and marginal parts of colony translucent, free from 

 zooids, but the marginal parts penetrated by vascular processes aris- 

 ing from the zooids and ending in bulbs, probably incipient buds. 

 The zooids lie somewhat below the surface in a single layer rather 

 closely placed, but between them are extensive common cloacal ducts 

 or canals. Each colony probably contains only a single complex 

 system with a centrally placed common cloacal 

 aperture. The basal portions of the colony are 

 of solid translucent test substance containing 

 closely packed bladder cells, small irregularly 

 shaped cells, and also larger round cells, which 

 may be symbiotic algae. These are, in the pre- 

 served specimens, almost colorless. 



Zooids smaller than those of the last-described 

 species, being generally considerably under 1 

 mm. long in the contracted state, and as noted Fl0 no.— leptocli. 

 below they have fewer tentacles and fewer NDM camficiformb 

 stigmata in a row. They resemble them, how- x 50 

 ever, in most characters, including, as far as 

 could be detected, the absence of an atrial languet or atrial siphon. 

 The branchial apertures are not always distinctly lobed. 



Mantle musculature insignificant; a few slender longitudinal bands 

 are present on the thorax. 



Tentacles of two sizes, arranged in alternation. 



Dorsal languets not demonstrated. 



Branchial sac with 4 rows of stigmata ; 8 or 9 on each side in the 

 anterior rows, but apparently only 7 in the last row. 



Stomach elliptical, somewhat elongated. 



Reproductive organs were found only in a few of the zooids ex- 

 amined. The male organs resemble those of the species just de- 

 scribed. The two testes were in all cases small and were appar- 

 ently not fully developed. 



Two colonies (No. 14) (Cat. No. 5956, U.S.N.M.), in the collec- 

 tion, both from Marongas Island, near Jolo, February 10, 1908. 



Four small colonies in the United States National Museum, col- 

 lected by Dr. L. E. Griffin and Mr. L. D. Wharton at Bantayan, may 

 also belong here but are too immature and present too few distinctive 

 characters for certain identification. 

 101825°— Bull. 100—17— 11 



