FLORIDAN BRYOZOA. 69 



Retepora reticulata l ) (Pl. XIII, figs. 242—244). 



Char.: Reteporce Beaniante varietas aviculariis majoribus elongate-spathulatis mu- 

 nita, apertura secundaria zooeciorum vulgo magis aperta. 



Hab.: In profunditate 270 orgyarura raaris extra Havannam hane varietatem ce- 



plt POURTALES. 



The only specimen which was sent me for examination, is the type-specimen for 

 the Cellepora reticulata, Pourt. ; and this proves to be a slightly marked variety of the 

 common Retepora. Beaniana. The great avicularium - - for, in the whole colony, I 

 can not see more than one of that kind - - with its decnmbent, almost linear, trans- 

 versely placed aperture, is rather a transformation of the zooecion beneath, whose aper- 

 ture at least is covered by the apertural part of the avicularium. This feature, indeed, 

 has never been observed in the typical Retepora Beaniana., and, in addition to the ge- 

 nerally more rounded and open secondary zooecial aperture, if proved, by further in- 

 vestigation, to be of a constant occurence, will make a distinct form, perhaps, of the 

 Floridan variety, although in all other essential points it seems to agree with the ty- 

 pical form. 



The difference between the Retepora Beaniana and Ret. cellulosa is quite analo- 

 gous with that between the Eschara (Porella) loevis and the Retepora rosacea. Hence, 

 as the first-named species, through the variations in the developrneot of its oral avi- 

 cularia 2 ), can not be separated from the second but for the presence of a txuly me- 

 dian oral avicularium, either the Retepora Beaniana, for that character, must be thrown 

 into the same genus with the Eschara (Porella) losvis, or all the named species must 

 be united into one and the same genus. It is a matter of agreement, how far to pro- 

 ceed in the establishing of generic divisions; but, as the Retepora Beaniana, through 

 the form of its first zooecia, as it occurs, sometimes 3 ), in a Lepralian (auett.) stage, 

 evidently has proved to be of the formerly so named Discoporidan type, we are obli- 

 ged to reunite the three families Escharidce, Discoporidce and Reteporidw, which were 

 formerly acknowledged. 



Discopora advena (Pl. XII, hg. 232). 



Char.: Zooecia rotundate-rhombica vel fere rectangularia, ventricosa frontem im- 

 perforatam, aperturam semiellipticam vel semicircularem praebent cujus latitudo circ. 

 = 0,16 mm.) setis marginalibus 6 vel 7 munitam, margine proximali recto bisinuatam, 

 aviculario acuto, obliquo, apertura? proximaliter apposito muniuntur. 



Hab.: In mari ad Floridam e proff. 79 et 116 orgyarum hane speciem Coralia 

 obducentem cepit Pourtales, quam in Museo Brittico e mari Chinensi apportatam vidi. 



With a true Escharidan shape of the zooecia, in a very pure condition, this spe- 

 cies combines that peculiar form of the proximal margin of the zooecial aperture, which 



1 ) Cellepora reticulata, Pourt., Bull. Mus. Conip. Zoöl. Cambv. N:o 6, p. 110. 



2 ) Seu Öfvers. Vet. Akad. Förh. 1867, p. 487! 



3 



) Ofvers. Vet. Akad. Förli. 1867, Bih., p. 200. 



