Manchester Memoirs, Vol. lix. (191 5), No. \. 23 



quadrangular. The length of the largest colony is 

 approximately the same. The axis ends at the base of 

 the apical polyp. The more obvious distinctions between 

 my specimen and Umbellula carpenteri are as follows : — 



The spicules are found not only in the lowest part of 

 the stalk, but all over the colony including the tentacles 

 of the autozooids. The length of the body of the auto- 

 zooid is distinctly longer in my specimen, viz., 26 mm. in 

 contrast to 14 or 15 mm. in Kolliker's specimen. The 

 length of the autozooid (including tentacles) is smaller in 

 my specimen, namely, 33 mm. as against 43-83 mm. in 

 Kolliker's specimen. Jungersen gives the length of the 

 tentacles in Umbellula carpenteri as being 10, 15 and 

 20 mm. ; in my specimen they are only 8 mm. The cal- 

 careous corpuscles described for Umbellula carpenteri are 

 much shorter, namely, 0012 mm. as compared with 

 O'liomm. in my specimen. Further, no nuclei in those 

 corpuscles such as described for Umbellula carpenteri are 

 seen. 



The species Umbellula rigida, Kiikth. U. Kbllikeri, 

 Kiikth. and U. carpenteri, Koll., are very closely allied. 

 I am doubtful whether the two former species should 

 ever have been regarded and named as separate species. 

 Further, Kiikenthal and Broch have made some mistake 

 in their Memoir in drawing up the distinctions between 

 those forms regarding the relative length of tentacle and 

 autozooids, and contradict themselves. In comparing 

 U. rigida, Kiikth., and U carpenteri, Koll., they say : 

 " Auch sind bei letzterer Form die Tentakel langer als dcr 

 Polypenkorper bei U. carpenteri, nach der Zeichnungen 

 zu erteilen, kurzer " (pp. 293 and 294. " Valdivia " Report). 



In comparing U. carpenteri and U. Kbllikeri, Kiikth. 

 They write " Auch sind die Tentakel langer wie der 

 Polypenkorper, bei U. Kollikeri dagegen bedeuUnd 



