FLORIDAN BRYOZOA. 57 



ally, it is yet more ventricose. As the distal end of the zooecion, priraarily, is sunken 

 to a level with the limitar furrows, in the secondary aperture, as it raises itself to a 

 horizontal level with the middle of the front wall, this raising, of course, must be 

 greatest in the distal part of this aperture. Thus it reminds us of the Escharella (Le- 

 pralia) cucullata, as described by Busk *), from what species, however, it is distinguish- 

 ed by the front wall being porous instead of granular. So, also, Lamouroux descri- 

 bed his Flustra torquata; and, indeed, the only synonyme, which seems to be sure 

 enough, is the figure by Savigny, namecl, by Audouin, Cellepora Mangnevillana. 



The ooecia are high and swollen, although a little flattened, usually, in the cir- 

 cumference of their mouth. On the specimen examined, I do not see any avicularia. 



This specimen, a very well outgrown colony, growing on a Nullipore, was taken 

 by Pourtales, W. of Tortugas, at the depth of 37 fathoms. 



The contraction in the middle of the zooecial aperture, with this species combi- 

 nes the 



Escharella depressa 2 ) (Pl. X, figs. 203—206). 



The hrst description of this species, with which we are able, with certainty, to 

 identify the two Floridan forms, is that given by Busk, notwithstanding some slight 

 differences in the manner of calcification, which seem to make a distinct variety of the 

 Mediterranean form. In the Floridan sea, it occurs in two well-distinguished forms, 

 which, as they seem to be constant enough, may well deserve their own names. 



E. rostrigera (figs. 203—205). 



Char.: Zooecia rectangularia vel ovato-rhombica, convexa vel fere plana, porösa 

 vel, calcificatione progrediente, fronte imperforata, ad marginem solum porösa, parie- 

 tem vulgo ad marginem distalem magis spissant; aperturam rotundate-rectangularem 

 in mediis lateribus constringunt, (vel majorem, latiorem, etiam transverse ellipticam, 

 margine proximali concavam, in angulis lateralibus dentatam prasbent); aviculariis acu- 

 tis, ad latera aperturse vel inter illam et marginem distalem transverse positis, cuspide 

 convergentibus, vel vibraculario uno in hoc loco muniuntur. 



Hab.: In proff 35 et 43 orgyarum hane formam Coralia et Bryozoa investientem 

 haud frequentem cepit Pourtales. 



This form, in its varying degrees of calcification, is the most aberrant from the 

 Mediterranean form, as known by the description by Busk. The most peculiar feature 

 is the occurrence of greater zooecia among the ordinary ones, in connexion, then, with 

 a great difference in the form as well as in the size of their aperture. This peculiar- 

 ity we have remarked, also, on the above-named Escharella sanguinea, without being 



J ) Cat. Brit. Mus. Polyz., p. 81. 



2 ) (?) Flustra Marcelii, Aud. in Savigny, Descr. de VEgypte, Polypes, tab. IX fig. 4. 

 Lepralia depressa, Busk, Cat. Brit. Mus., Polyz., p. 75, tab. XCI figg. 3 et 4. 



K. Vet. AkaJ. Hand). Ii. 11. N:o 4. 



