PACIFIC TUNICATA OF U.S. NATIONAL MUSEUM 119 



Description. — A single, elongated, cylindrical colony from the 

 Philippines, 20 mm. long and about 3 mm. thick, densely encrusted 

 with sand grains on the surface, was examined. 



Zooids about 5 mm. in length, abdomen two to three times as long 

 as contracted thorax. About 8 longitudinal and about 30 fine trans- 

 verse muscles on each side of thorax; about 10 stigmata in each of 

 three rows. 



Eemarks. — Longitudinal and transverse thoracic muscles of the 

 present form numl)er as many as in Eudistoma toharae^ but consider- 

 ably fewer than in E. siiakdbrl Tokioka in which 20-35 longitudinal 

 muscles and up to 65 transverse muscles are defuied. On the other 

 hand, the appearance of the colony closely resembles that of E. snak- 

 ah?'?', being densely encrusted with sand grains all over the surface. 

 Thus, it is not impossible that the present specimen represents a young 

 colony of E. snakahri, including zooids having fewer muscles. How- 

 ever it seems more reasonable to treat the present specimen as an un- 

 usual colony of E. tokarae, which is carrying sand grains on the surface. 



51. Eudistoma laysani (Sluiler) 



FiGUKE 42 



Distoma laysani Sluiter, 1900, p. 9, pi. 1, fig. 2; pi. 2, fig. 7. 

 Polycitor laysani Sluiter, 1909, p. 4. 



MATERIAL EXAMINED 



Palau Islands : Madalai district, west end of Koror Island ; GVF sta. 12. One 

 colony (USNM 11401). 



Description. — A single colony from the Palau Islands consisting of 

 13 cormidia and a large common basal mass Avhich is 50 mm. X 19 mm. 

 in extent and 23 mm. in thickness was examined. 



Cormidia all exposed, somewhat irregularly shaped, some divided 

 distally into two tips; the largest 12 mm. long and 8 mm. in diameter. 

 Basal mass generally purplish gray, and at basal parts contains many 

 fecal pellets which add a brownish-yellow tint. Upper surface of 

 basal mass covered with mud and small algae between cormidia. Test 

 soft, but tough and opaque. Zooids very long. Thoraces embedded 

 in corona of cormidium, about 1 mm. long in a contracted state; 

 faintly purplish brown. Abdomens much longer, up to 15 mm., em- 

 bedded deeply in basal mass. Probably posterior part of abdomen 

 containing gonads and stomach was orange red in living animal. Both 

 apertures 6-lobed, atrial siphon always smaller and situated somewhat 

 posteriorly to branchial siphon. About 20 (22 for example) longi- 

 tudinal and 40-50 very fine transvei'se muscles on each side of thorax. 

 Longitudinal muscles run onto abdomen, but are not united into mnscu- 

 lar bands at neck region ; transverse muscles confined to stigma! al area. 

 About 15 stigmata in each of three rows; a few dorsal stigmata of the 

 first row arranged along dorsomedian line. Dorsal languets distinct, 



