102 THE CRAG POLYZOA. 



8. H. LUNATA (. Sp.~) PI. XVI, fig. 4. 



Polyzoario erecto (?) ; rainis furcatis, subcylindricis. Superficie anteriori indistincte 

 fibro-reticulata, porosa ; posteriori obscure sulcata, minute punctata. Cellularum orificiis 

 lunatis vel suborbicularibus, integris, superficie sequatis. 



Polyzoarium erect (?) composed of forked, subcylindrical branches ; mouths of cells * 

 lunate or suborbioular, simple, even with the surface; anterior surface indistinctly fibro- 

 reticulate, punctured ; posterior obscurely sulcate, finely punctate. 



Habitat. C. Crag, S. Wood. 



The peculiar form of the mouth in this species renders it easy of recognition. As it 

 occurs but sparingly and only in small broken fragments, the real character of the growth 

 cannot be ascertained, but from what is apparent it was probably of small size, and con- 

 sisted of irregular, tolerably straight, forked branches. 



9. H. FRONDICULATA, Lamouwux. PI. XV, figs. 1, 2; PI. XVI, fig. 6. 



Polyzoario subexplanato ; ramis irregularibus e trunco forti surgentibus, cylindricis, 

 teretibus vel subcompressis. Superficie anteriori reticulato-fibrosa, porosa vel cribriform! ; 

 posteriori reticulato-fibrosa, costulis granulosis, glabrisve, sulcis poros elongates gerentibus. 

 Cellularum orificiis prominulis, einarginatis sen potius bifidis. 



Polyzoarium irregularly branched, usually in one plane, and springing from a strong 

 stern ; branches cylindrical and tapering, or compressed ; anterior surface strongly fibro- 

 reticulate, irregularly punctured or cribriform iu the rhomboidal spaces enclosing the 

 mouths of the cells ; mouth of cell exserted, emarginate, thence bifid ; posterior surface 

 reticulato-fibrous, granular or smooth, with elongated pores in the fissures. 



HORKERA FRONDICULATA, Lamx. ; Milne Edwards; Elainvi/le (not Busk), Ann. N. H. 2d 



ser., xiii, p. 34. 



KETEPORA FRONDICULATA, Lamarck. 



MILLEPORA TUBIPOKA, Ellis and Solander, p. 139, pi. xxvi, fig. 1. 

 MILLEPORA LICHEN GIBES, Linn.; Pallas ; Esper. 

 HORNERA AFFINIS, M. Edwards, 1. c., 19, pi. x, fig. 1. 

 HORNERA ANDEGAVENSIS, Michelin, Icon. Zoophyt., p. 318, pi. Ixxvi, fig. 8. 



Habitat. C. Crag, S. Wood; Upper Tertiaries of Sicily, M. Edwards; Doue, Mich. 



The remarkable difference in the appearance of this species, as shown in our figures of 

 the natural size (figs. 1, 2, PI. II, and fig. 6, PI. Ill), and that represented, for instance, 

 in M. M. Edwards' figure of the recent //. frondiculata, would startle any one not 



