156 ■ ME. A. W. WATEES ON 



The tubules are not to be looked upon as belonging to the 

 zooecia, but as being of equal individual importance with the zooecia. 

 My sections of the living Diastojoor a ohelia are not sufficient to enable 

 me to give a full description of these tubules, and during a recent 

 short visit to the Zoological Station at Trieste this species was not 

 met with, although the writer was specially on the look-out for it. 



There are also from the same localities adnate specimens of fossil 

 Diastojwra, with similar zocecia and similar tubules, and seeing that 

 these very exceptional characters are the same in both there seems 

 sufficient reason for considering them as stages of the same thing. 

 Again, from Malo there are a number of specimens without tubules, 

 but in shape and growth exactly resembling the erect Diastopora 

 hrendolensis. These Malo forms are no doubt the D. coinpressa of 

 Eeuss, though the two may have to be united. It may be asked 

 whether the tubules depend on the condition of growth. 



Log. Brendola ; Yal di Lonte ; jSTovezzina (Ferrara di Monte 

 Ealdo); Malo. 



5. Idmonea concava (Eeuss). 



Idmonea concava, Heuss, Bry. von Crosaro, p. 282, pi. xxxv. 

 figs. 3, 4; Olig. von Gaas, p. 478 ; Waters, Ann. Mag. Nat. Hist. 

 ser. 5, vol. iii. p. 271 ; Seg. Porm. Terz. Eeggio, pp. 209, 297, 330, 

 371 ; Meunier & Pergens, Bry. du Syst. Moiit. p. 13 ; Pergens, 

 Bry. von "Woia Lu'zanska, p. 62. 



Idmonea gracillima, Peuss (non Busk), Bry. von Crosaro, p. 282 ; 

 Pergens, Bry. Poss. de Kolosvar, p. 6 ; Bry. von Wola Lu'zanska, 

 p. 63. 



There is sometimes considerable difference in the dorsal surface of 

 a specimen, part being very distinctly concave while the rest is 

 almost fiat or even convex, and as /. concava and gracillima were 

 separated only on account of the characters of the dorsal surface I 

 am convinced that they should be united. I would j)oint out that 

 in almost every locality where one of these forms has been found the 

 other occurs also. Dr. Pergens gives a list of ten Hungarian localities 

 where both occur, and this constant appearance together in beds of 

 various ages, and widely separated, should alone make us suspect 

 their identity. 



Log. Yal di Lonte ; Montecchio Maggiore ; Brendola ; Perrara di 

 Monte Baldo ; Crosaro ; Malo ; Mons (Belgium) ; Wola Lu'zanska ; 

 Hungary (Perg.) ; South Bavarian Eocene, Gaas ; Pliocene, Italy. 

 Living: Mediterranean. 



6. Idmonea eeticulata (Peuss). (PI. III. fig. 10.) 



Idmonea (Crisina) reticulata, Keuss, Bry. von Crosaro, p. 281, 

 pi. xxxiv. fig. 13. 



This is a very interesting species, as showing the Idmonea 

 arrangement of the zooecia on the front, whereas the pitted structure 

 on the dorsal surface is a character frequently occurring in Honiera, 

 but not in Idmonea. I. reticulata is very closely allied to, if not 

 identical with Crisina triangulai^is, d'Orb., Pal. Pranc. -p. 915. 



