678 



SILURIAN CORALS. 



pores or foramina on the side of one branch have united by growth to those on the side of the 

 adjoining branch, and constitute solid bars, either stretching transversely and simply across the 

 intervals, or uniting obliquely three and sometimes more together. 



Figs. 15, a, h, c. partly exhibit the changes effected by growth in this genus, the figures with 

 an asterisk being magnified. 



Figs. 15, 15*. This specimen consists of several detached branches fixed to an organic body. 

 The pores or foramina project from the sides of the branches, but are not united. In this spe- 

 cimen both the external and internal structure are exposed. 



Figs. 15 a, 15 a*, 15 b, 15 b*. The foramina in several of the rows exhibited in these figures 

 are united, and nearly level with the surface of the branches ; in others they are not quite united, 

 or are depressed in the centre. 



Figs. 15 c, 15 c*. The union of the foramina in this specimen is complete throughout, and the 

 bars are all on a level with the branches. 



It is very difficult to establish species from fragments, but the four following are believed to 

 be distinct from each other. 

 Fenestella antiqua, Lons. PI. 15. f. 16, 16 a nat. size and magnified twice. 



F. Branches bifurcated, rather distant, transverse processes very apparent, giving the exterior 

 a quadrangular net- work character ; foramina or pores not numerous nor close. Nature of the 

 interior reticulation not ascertained. 



Syn. and Ref. Gorgonia antiqua? Goldfuss, Petref. p. 99. Taf. XXXVI. f. 3 a. 1826. 



Formation and locality in England. Wen lock Limestone, Dudley. 



Foreign locality and authority. Eifel, Goldfuss. 

 Fenestella Milleri, sp. n. Lons. PI. 15. f. 17. magnified 2£ times. 



F. Outer surface, branches very thin, knife-edged, close together, regularly bifurcated : pores 



on the sides of the branches very small, most apparent in the upper part : transverse processes 



thin, rather distant, not very distinct : opposite or inner side, regular net- work. 



Formation and locality. Wenlock Limestone, Dudley. 

 Fenestella prisca, Lons. PI. 15. f. 18, 18 a to 18 c. — 18, 18 a nat. size and magnified thrice, 18 h 



external surface worn, 18 c inner surface of the same. 



F. Branches externally slender, generally near each other, bifurcated ; foramina numerous and 

 close : in the internal net- work, the intervals are oval or oblong with rounded angles, and very 

 variable in size. 



The specimen (f. 18.) is from near the base of the coral, but in other specimens, apparently 

 from the upper part, the foramina are equally numerous. The figures 15, &c. apparently be- 

 long to this species. 



Syn. and Ref. Retepora prisca, Goldfuss, Petref. p. 103, Taf. XXXVI. f. 19. The worn 

 specimen from Dudley, represented in PI. 15. f. 18 b., strongly resembles Goldfuss's coral. 

 Formation and locality in England. Wenlock Limestone, Dudley, 

 Foreign locality and authority. Eifel, Goldfuss. 

 Fenestella reticulata, Lons. PI. 15. f. 19, 19 a nat. size and magnified 2± times. 



F. Branches irregularly anastomosed : foramina large, rather distant : reticulation of the inner 

 surface similar to that of the external. 



Syn. and Ref. Retepora reticulata ? Hisinger, Lethsea Suecica, p. 103. Tab. XXIX. f. 8. 

 Formation and locality in England. Wenlock Limestone, Dudley. 

 Foreign locality and authority. Gothland ? Hisinger. 



