Mr. R. Etheridge on Carhoniferoas Polyzoa. 37 



of which are sometimes separated by more or less flexuous lon- 

 gitudinal ridges ; interspaces usually rather thick, and not 

 pierced by transverse pores, but occupied by very minute, non- 

 septate longitudinal cells that are closed and represented at the 

 surface by minute granules or spinules." 



Mr. Meek considered t\\?it MUlepora rhombifera^ PhilL, Vin- 

 cularia ornata, Eicliw., and Favosites senalis, Portlock, might, 

 "with much confidence, be included in this genus." The tirst 

 of these has been shown by the Messrs. Young to be a species 

 of their genus Bhabdomesow, but with regard to the others I 

 am not in a position to form an opinion. Mr. Meek concluded 

 his description with this remark : — " Although some species 

 of this genus [Rhoinhojjora] have been referred to Goldfuss's 

 genus Vincularia, they are widely removed from the typical 

 Cretaceous species of that genus." I think it probable that 

 Rhomhopora will be found a very convenient one for numerous 

 small Polyzoa of our Carboniferous and, perhaps, Silurian 

 rocks, the generic affinities of which have often been a 

 stumbling-block to authors. The relation of Rhomhopora to 

 Vincularia requires investigation ; but I would in the mean 

 time suggest an examination (to those who have well-preserved 

 specimens) of the following species : — Vincularia ornata, 

 Eichw. ; V. muricata, Eichw. ; V. Benniei^ mihi ; Cerio- 

 pora hamiltonensisj Nicholson ; Millepora interporosa^ Phill. ; 

 M. oculata^ PhilL; M. spicularis^ Phill.; and M. similis^ 

 Phill. 



Rhomhopora has been adopted by Dr. Toula * for certain 

 forms from the Permio- Carboniferous rocks of Spitzbergen. 



EXPLANATION OF PLATE II. a. 



Fig. 1. Fenestella arctica, Salter, var. scotiea, K. Eth., LoTver Carboni- 

 ferous Limestone group, Currielee Quarry, Edrnburghsliire. 

 Nat. size. 



Fig. 2. A small portion, much enlarged, non-poriferous face, to show the 

 zigzag interstices and hexagonal fenestrules. 



Fig. 3. Gktuconome elegantula, R. Eth., Lower Carboniferous Limestone 

 group, Harelaw Quarry, Haddingtonshire ; poriferous fitce, some- 

 what enlarged. 



Fig. 4. A portion of tig. 3, much enlarged. 



Fig. 6. Another specimen of the same, striated or non-poriferous face, 

 nat. size., Harelaw Quarry, Haddingtonshire. 



Fig. 6. A portion of fig. 5, much enlarged. 



(I am indebted to Mr. Wilson for the drawings.) 

 • Sitz. d. k.-k, .\kad. d. Wisseuschaftcu zii Wieu, \67i'). ].\.\i. 



