124 UNITED STATES NATIONAL MUSEUM BULLETIN 251 



55. Eudisloma albatrossae, new species 



Figure 44 



HoLOTYrE. — USNM 11811: Japan; off Omai Zaki Light, Honshu, 

 N. 17° E.J 9.7 mi.; 34-37 fath., mud, gravel and rock; Albatross sta. 

 3730, May 16, 1900. 



Paratype.— USNM 11812 : same data. 



Description. — Two colonies dredged near Japan in the western 

 Pacific were examined, each consisting of a roundish corona and an 

 elongated peduncle attached to a mass of sponges. One specimen 

 (fig. 44a) has a comparatively large corona, 17.5 mm. m length and 

 14 mm. in diameter, and a stout peduncle, 24 mm. long and 8.5 mm. 

 thick; in the other colony, the corona is nearly spherical and very 

 small, only 7.5 mm. long, and the peduncle is longer and much thinner 

 than in the former, 38 mm. long and less than 5 mm. in diameter. 



Test faintly whitish yellow, very soft at corona, but hard, gelatinous, 

 or rather cartilaginous and translucent at other portions. Surface 

 of test smooth, although some foreign matter found on peduncle. 

 No system found in arrangement of zooids. Largest zooid examined 

 is 4 mm. in length. Abdomen approximately 21/^ times as long as 

 contracted thorax. In smaller colony all zooids found in resting stage, 

 generally 2 mm. in length, constituted of abdomen and rudimentary 

 thorax, but never provided with a fully developed thorax. Both 

 apertures G-lobed, about 8 longitudinal muscles on each side of thorax. 

 About a dozen ( ? ) stigmata in each of three rows. Tentacles about 8 

 ( ? ) , ciliated groove a small oval opening. Rudimentary thoraces of 

 zooids found in smaller colony attain one-fifth of abdomen's length. 

 Cardiac end of stomach situated approximately at level of posterior 

 one-third of abdomen. Hind stomach very stout, midintestinal por- 

 tion rather long; proximal end of rectum slightly constricted from 

 preceding part of alimentary canal, but never forming a caecum 

 there. Two pairs of longitudinal muscular bands run along abdomen. 

 In zooids of smaller colony in resting stage alimentary canal wholly 

 embedded in thick mesenchyme tissue. Stomach occupies anterior 

 half of abdomen, both hind stomach and middle intestine ai*e well 

 defined, although boundary between stomach and hind stomach be- 

 comes somewhat obscure in some zooids. IMiddle intestine much 

 longer than hind stomach and markedly constricted near middle. 

 Proximal end of the rectum does not form a caecum. Rectum is 

 generally thin. Gonads not found in any examined zooids. 



Hypodistoma, new genus 



Type species : Distoma deerrata Sluiter, 1895, from Thursday Island. 

 The atrial aperture of respective zooids opens to the lacunae system 

 of the colony, which is then connected to the exterior through common 

 cloacal apertures. The atrial siphon issues from the dorsoposterior 

 part of the thorax. Other structures are the same as in Evdistoma. 



