Mediterranean 'I'crvia and Idtnonoii. '• 



described by thcin. Two iiiiportuiit characters usually 

 occurring arc the hollow dorsal surface and the considerable 

 contortion of the zoarium,so that the plane may be changed 

 with a new branch as in /. notoinafe. Apparently it is a 

 widely spread species in the European Tcrtiaries, and I have 

 nn-ently found it from the Vicentine BaJtonian in Brendola, 

 !Montecchio Ma;,'giore, and Creazzo. 



Loc. Capri, Oran (Aljjiers). 



Fossil. Pliocene, Postplioeene of Italy. I do not give full 

 lists of the later Italian Tcrtiaries, as at first intended, as 

 there is so much uncertainty until the ovicells are studied. 



Idmonea athinticn, Johnston. 

 (PI. I. Hgs. 11, 12; PI. II. Hg. 9.) 



Idmonea aHnntica, Johnston, British Zoophytes, ed. ii. p. 278, pi. xlviii . 

 Hg. 3 (iai7). 



The typical /. atlantica, as described and figured by 

 Johnston, is narrow and tapers to tlie end, which is usually 

 the case in specimens from the Mediterranean and from 

 distant localities. The bifurcation is slightly rounded at 

 the base, then the separation is at a moderate angle, after 

 which, in the most typical specimens, the branches do not 

 spread out far, but continue somewhat parallel, as Ilarmer 

 has called it a tuning-fork shape. The branches in the older 

 parts arc usually somewhat rounded on the dorsal surface, 

 but elsewhere Hat or somewhat concave. The parallel 

 branches arc shown in Buck's Brit. ]\Ius. Cat. (pi. ix., figure, 

 natural size, right bottom corner: the figures are unnum- 

 bered). The two figures at the top have short interuodes, 

 and I do not think they are /. atUintica. llincks shows the 

 same j)arallel growth, as also does LJusk in ' Polyzoa of Norway 

 ami Finland' (pi. i. fig. (\) , and here he says "in external habit 

 it much resembles /. radians, Lam." 



In typical s|)ecimens in my collection from various places 

 the zoarium is long and usually straight, with very long 

 internodes (one fi'om Xai)lcs is 15 mm. long), the ovicells 

 are lon;j^ and very much raised, occupying the width of the 

 zoarium, with the series only just showing — they are not 

 usually near to a bifurcation ; but besides the more typical 

 form there are frequently zoaria, with short triangular 

 ovicells, which at one time it seemed would liave to be 

 separateil from the more ty[)ical ones. 



On one specimen there is a rather long ovicell, just below 



