PACIFIC TUNICATA OF U.S. NATIONAL MUSEUM 



31 





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'>Vd ' • -^ Figure 5. — Ainaroucium glabrum Vcriill: lar\a, right side of trunk. 



witli sand grains, with wliich tlic test is also impreo-natod, as seen in 

 the colony from Albatross sta. 4993 (11778), which consists of the 

 exposed, whitish, and nearly opaque corona and the basal peduncular 

 portion covered with sand grains (fig. 125). System of zooid ar- 

 rangement obscure. Zooids situated obliquely (?), all contracted 

 rather strongly, being 2-3.3 mm, in length. Zooids reddish brown 

 and faintly visible through test in some colonies. Abdomen half as 

 long as thorax or nearly equal to the latter in a strongly contracted 

 state. PovStabdomen varies considerably in length; most frequently 

 as long as thorax and abdomen measured together in a contracted state, 

 reaching 11-12 mm. in some zooids. Branchial aperture 0-lobed, 

 atrial languet with simple tip. Longitudinal muscles 8-15 on each 



