FL0R1DAN BEYOZOA. 67 



colonies, in considering the differences between the individuals of different colonial 

 age, we have seen all the escharine types to be starting out from a common, mem- 

 braniporidan origin, it is a natnral consequence, these types in many ways will run 

 together again; but, for holding together, systematically, the nearest allies, we arrange 

 them into systematical families, whose significance most easily will be understood, bj r 

 comparing their representatives of corresponding typical developraent. These represen- 

 tatives Ave may cite: 



Porellina ciliata for the faniily Eschariporidae, 



Hippothoa spinifera Myriozoidae, 



Discopora emucronata 1 ) Escharidae, 



as the last-named farnily now will be appreciated. 



By this arrangement, I think, all the known escharines (and celleporines) will 

 fmd a natural place in the system, if compared with any one of these representatives 

 or with some of their relatives. As easily will be seen, in their typical, primary con- 

 stitution, the named three families are characterised : the first by its median pore, the 

 second by its median sinus, the third by its wanting of both. 



To this restriction of the number of the families of this group, 1 håve been led, 

 particularly, by the constitution of one of the Floridan Retepora?, as that genus for- 

 merly was acknowledged. This species is nothing else than the wellknown Retepora 

 cellulosa, but as it occurs here in a variety of high systematical interest and of very 

 characteristical constitution, it may well deserve its own name, 



Retepora marsupiata 2 ) (Pl. XIII, figs. 245 — 254). 



Char.: Zooecia ovata, postreino magis minusve cylindracea stirpem retiformem ex- 

 struunt, aperturam primariam (cujus latitudo circ. = 0,os mm.) sernicircularem, fere 

 horizontalem (in piano frontis zocecii positam) pra;bent, secundariam vero aperturam 

 primo elevatain, tubiformem, proximaliter sinuatam (ubi igitur, tubo accrescente, extus 

 bisulcata fit), calcificatione progrediente deinde immersam; aviculario orali, laterali, ob- 

 liquo muniuntur, rotundo vel acuto, in apertura secundaria immerso vel in rostri obli- 

 qui formam erecto. Ocecia rotunda rima frontali aperiuntur. 



Hab.: Variis in profunditatibus (16 — 262 orgyarum) ma ris Floridani hane for- 

 mam viventem cepit Pouetales. In mari ad insulam Teneriffa secundum Busk vivit. 



In their primary state, the zooecia are hyaline, without pores, elongated ovate, 

 with their front-side slightly convex and marked from the lateral sides by a longitn- 

 dinal crest. Inside this crest, sometimes a few depressions are to be seen, indicating, 

 perhaps, some formation of secondary pores, although these never seem to attain any 



J ) Öfvers. Vet, Akad Förh. 1871, p. 1129. 



2 ) ? Plridolopora labiata, Gabb et Horn, Monogr. Pohjz. Scc. Tert. Form. N. Amer., Journ. Acad. Nat. Se. 



Philadelphia, vol. V p. 138, tab. XIX fig. 21 



Retepora marsupiata, Busk, mscrpt. 



