6 ' :\Ir. A. W. Waters on 



muiibrr of isolated zooecia, disposed without order on the 

 iniildlc of tlio branclirs l)et\veen the hitcral series. Idmonea, 

 as we now undcistaml it, has ovicells on the anterior snrface 

 or Lateral. 



Considerable numbers of zoaria may be found without any 

 ovicells, but, after looking through a large quantity of material, 

 my collection now contains a fair number with ovicells. 

 Comparison is very important, as it shows that, while the 

 ovicell may frequently occur near a bifurcation, this is by no 

 always the case. It may occur in the branch away from the 

 biiuication, ami there may be one at a bifurcation and another 

 further up quite independent. One occurs laterally (figs. 

 5, 6), so that it is seen from the back as well as the front. 

 There are one or two with a rather small ovicell near a 

 bifurcation, which also extends to the front (figs. 2, 7); on 

 another (figs. 3, 4) the ovicell is seen ou the anterior and 

 dorsal surface, another specimen is almost identical. A 

 similar ovicell was found by Harmer on a Queensland speci- 

 men, and ou this the species T. jelly ce^ was described. 

 Probably the specimen from Queensland described by Harmer 

 had been given by me to Miss Jelly without my appreciating 

 the importance of the ovicell, and on others from Holborn 

 Island, given me by Professor Haswell, I find no ovicells. 

 Although the series do not occur as much spread out as some 

 ^Mediterranean specimens, this may only be because they 

 are somewhat broken. The pores of my Mediterranean and 

 Queensland specimens seem to be identical, so that there is 

 no ground for retaining T.jellyce, H. 



The lateral ovicell (figs. 5, 6), of which only one case lias 

 been met \\iih, is extremely interesting, for Canu and Bassler 

 have made a genus, Pleuronema, principally based on the 

 ovicell of an Ic/niunea-^orm being lateral, so that if fig. 5 had 

 been found in a distant locality it might possibly have been 

 made the type of a new genus. One specimen of T. irregularis 

 has eight ovicells, some at a bifurcation, others ou the 

 brauches (fig. 9). 



The similarity of the ovicell and ooeciostome with the 

 anterior ovicell of several species of Crisia (a?;, for instance, 

 C.rauiosa) is very noticeable. 



Loc. Naples ; Capri ; Villefranche-sur-Mer ; Oran ; 

 Ajaccio, 280 met. ; Genoa ; Adriatic; Bay of Biscay, 135, 

 166, 240 met. ; Madeira ; Azores, 318 met. ; between Fa} al 



* "Poly, of the'Siboga' Exped.,"pt. 1, 'Siboga'Exped. xxviii.a, p. 14-3, 

 pi. xi. figs. 1-3 0915). 



