Note on Studeria mirabilis. By Prof. J. A. Thomson. 681 



Nidaliopsis, and that the nearest related form is Organidus. The 

 armature of the polyps in Nidalia, its unbranched habit, and many 

 other features separate it far from Paralcyonium, and Gersemia, to 

 which, as Kiikenthal has shown, Organidus must be referred, is 

 equally remote. 



AVe have not as yet been able to procure a specimen of Fasci- 

 cularia for examination, and we would not therefore dogmatically 

 exclude the possibility that Fascicularia, Paralcyonium, and 

 Studeria form a series showing the progressive differentiation of a 

 rigid basilar portion into which the rest of the colony can be 

 retracted. The descriptions given by Motz-Kossowska and Fage 

 are very precise, and their discussion of the possible relationships 

 is admirable ; what surprises us is that in spite of the differences 

 which they indicate between Fascicularia and Paralcyonium, they 

 should propose to include the two in one family. From their 

 descriptions, as from Yiguier's, it appears to us that Fascicularia is 

 more nearly related to Sym/podium than to Paralcyonium ; that it 

 differs from Paralcyonium too markedly (in the structure of the 

 basilar portion and in the relations of the polyps to this and to 

 one another) to allow of their being included in one family ; and 

 that neither is nearly related to Studeria. 



Diagnosis of Studeria. — A colony consisting of a strong densely 

 spiculose cup, within which very numerous finger-like polyp- 

 bearing lobes or branches are retracted ; these arise at different 

 levels from a strong muscular central thalamus, and from the upper 

 parts of the inner wall of the cup ; each finger-like lobe is thickly 

 covered with polyps and ends in a polyp larger than the rest ; the 

 cavities of the polyps communicate with a central canal in the 

 digitiform lobe, and these central canals unite in a few large 

 longitudinal canals with few spicules in their walls ; the polyps 

 have a distinct non-retractile calyx or verruca, covered with spindles 

 arranged in double rows ; the spicules are all spindles, except a 

 few minute irregular forms found (along with sparse spindles) in 

 the canal walls ; many of the cortical spindles attain huge dimen- 

 sions (over 9 mm.) ; many are sinuous and forked ; almost all are 

 very warty, and there is a characteristic arrangement of the warts in 

 transverse rows. 



Our general conclusion, which is based on a single specimen, 

 of which we had to be careful, is that we have to do with a, very 

 distinct genus, related to Paralcyonium, but not very closely ; 

 perhaps connected through forms like Nidalia with other Alcyo- 

 niidas ; but more probably deserving, as Professor Verrill suggested 

 to us, the establishment of a new family. 



Dec. 16th, 1908 2 z 



