FLORIDAN BEYOZOA. 37 



sides are a little more parallel; otherwise, tke typical form evidently is the same as 

 that of the apertures of the preceding species. Still, their margin here is a little more, 

 though feebly, raised into a free rim, which is continued, from the two proximal cor- 

 ners of the apertures, in two proximally converging lists, thus limiting a triangulär 

 depression, which calcifies more lately than the other part of the front side of the 

 zooscia. The pores on this front side are, relatively, very obvious, even at a low degree 

 of enlargement. In the usual manner, they are arranged quincuncially, though this 

 order, with aily irregularity in the growth of the zocecia, very easily will be dissolved. 



Irregularly distributed över the limitary furrows between the zooscia, some rounded, 

 wart-like avicularia are to be seen, whose plain tip is occupied by the round aperture, 

 with a semicircular mandible (operculum), whose breadth is about 0,oh mm. 



As we know the relation between the creeping and the erected states of the 

 Bryozoa, especially that of the Tessaradoma boreale, there can be no doubt, I think, 

 of these two species of Gemellvpora belonging to one and the same genus. Still, this, 

 in the following, will be shown so nearly to approach to some species of the genus 

 Escharella, that it is only for the convenience of holding together the nearest allied 

 species and for pointing out the different stages of the serial development of the escha- 

 rine type, that we here have established a new genus. A little more dimcult it seems 

 to be to decide, whether to that same genus will be referred the species, also, that 

 I name . 



Gemellipora glabra (Pl. XI, hgs. 207—210) *). 



Char. spec: Apertura zoceciorum partem distalem, quoe operculo clauditur, fere 

 rotundam (margine tres saltem partes periphericas circuli occupante), partem vero prox- 

 imalem trilobam praebet, quia sinus proxirnalis medianus, speciebus prascedentibus com- 

 paratus, valde angustus videtur et sinus laterales latitudine fere asquat vel illis parum 

 major est. 



1. Forma striatula; 



Char.: Colonia crustacea zoceciis elongate rhomboidalibus, modice ventricosis 

 vel fronte fere planis, poris punctatis, transverse rugosis, longitudinaliter delicatissime 

 undulato-striatis exstruitur. Ad partem distalem zoosciorum vel ocecia depressa, rotunda, 

 poris calcificationis punctata, poro speciali (apertura elliptica avicularii proximaliter 

 vergente) ad apicem perforata exsistunt, vel alia organa colonias secundi ordinis (avi- 

 cularia) minoris inagnitudinis, ambitus rectangularis, quse eodem modo poris calcifi- 

 cationis poroque speciali (apertura) perforantur, hunc locum tenent. 



2. Forma glabra (typica): 



Char.: Colonia in stirpis teretis, contigua? formam erecta, e qua rami multifarie 

 sparsi in rectam lineam divergunt, zoceciis primo porosis, vivis membrana calcarea nitida 

 obductis, calcificatione valida tectis exstruitur. Pars distalis pra?sertim junionun zooecio- 



\) (?) Flustret Gaiji, Aud., Savigny, Descr. de VEgypte, Polypes, pl. X, fig. 2. 



