462 TUBULIPORID^. 



DIASTOPORA OBELI A*, Johnston. 



Plate LXVI. figs. 10, 10 a. 



Ti'BuuroRA OBKLIA, Johnst. B. Z. ed. 1, 269, pi. xxxviii. figs. 7, 8. 

 DIASTOPORA OBBLIA, id. B. Z. ed. 2, 277, pi. ilvii. figs. 7, 8 : Smitt (1865) : 



.Btfo-A: fletfer: &c. 

 DIASTOPORA HYALINA, a, OBEMA (Johnst.), Smitt, loc. cit. (1866), 396 & 



421, pi. viii. figs. 9-12. 



Zoarium entirely adherent, indefinite in its growth, and of 

 irregular outline, edged by the basal lamina. Zooecia 

 arranged alternately, moderately slender, minutely 

 punctate, surface flattened, usually with only a short 

 portion of the anterior extremity free and suberect, 

 separated by distinct, semitransparent lines ; orifice sub- 

 circular : small tubules (secondary cells) interspersed 

 amongst the ordinary zooecia. Ooecia transversely ellip- 

 tical swellings involving several of the zooecial tubes. 



THE surface of the zoarium distinctly lineated by the 

 boundaries of the cells, and the numerous tubules distri- 

 buted amongst the zooscia, are the features by which this 

 species may be at once distinguished from the following. 

 The cells are also less crowded than in D. Sarniensis. 



The tubules are present in large numbers ; they are very 

 minute, and usually originate immediately behind the 

 ordinary zooecia, which they resemble closely in form. 

 Their use is unknown. 



The ocecium is very similar to that of the following 

 species. 



In some cases many of the cells are closed at the top ; 

 but they are never furnished with the tubular process 

 which occurs in D. Sarniensis. 



* This may be the Berenicea hyalina of Fleming ; but his description is 

 so little characteristic that thp identification cannot be made with any cer- 

 tainty, and I therefore retain Johnston's well-established name. 



