I 



BRITISH UPPER SILURIAN FENESTELLIDJi:. 249 



would regard them as " gemmuliferous vesicles " *. At any rate the 

 drawings and description of this species are so circumstantial that we 

 cannot do otherwise than retain it, notwithstanding the doubts I 

 have expressed as to its identity. 



Tenestella reteporata, sp. nov. Plate XI. figs. 1-1 c. 



Sp. char. Polyzoary, base conical, opening outwards, forming ex- 

 pansions of considerable size. Interstices — obverse, strong, sinuous, 

 keeled, rounded, often angular from erosion ; reverse, striated longi- 

 tudinally : four interstices in the space of two lines transversely. 

 Keel strong, rounded. Dissepiments often less in size than interstices, 

 recessed, not so wide as fenestrules, giving in consequence a waved 

 line to the interstice ; two dissepiments in the space of two lines 

 longitudinally. Pores small, circular, less than their diameter apart 

 when not worn down ; from eight to thirteen pores between 

 dissepiments. Penes trules irregular, oblong, narrower at either end, 

 twice as long as broad. 



Obs. There is no fear of confusing this species with either of the 

 other Dudley forms. Its ample size, irregular habits of growth, 

 and large number of pores between dissepiments are its distin- 

 guishing features, and clearly mark its identity. I shall allude later 

 on to the interest attaching to this species on account of its possessing 

 traces of its relation with the genus Betepora, which, while abundant 

 in the beds below, has not as yet been found in the Dudley beds. 



Locality. "Wenlock Limestone near Dudley. 



Pexestella lineata, sp. nov. Plate XI. figs. 2, 2 a. 



Sp. char. Polyzoary, base strong, cylindrical or conical, attachment 

 solid; growth, rapidly opening outwards, forming wide funnel- 

 shaped expansions, folded or plaited on their outer margins. Five or 

 six inches in diameter. Interstices on the poriferous face, keeled, 

 rounded when perfect, often angular from erosion ; reverse, finely 

 striated longitudinally : ten interstices in the space of two lines 

 transversely. Keel fine, straight, with slight prominences ; as 

 seen when freshly or partially weathered out, it appears as a series 

 of very regular and parallel lines, suggestive of its specific name. 

 Dissepiments on pore-face thin, recessed, often expanding at the 

 junction with the interstice ; seven dissepiments in the space of two 

 lines longitudinally. Pores placed on the outer surface of the poly- 

 zoarium, smaU, round, prominent, own diameter apart, one or two 

 between dissepiments, and one in each angle formed by the junction 

 of dissepiment with interstice ; latter feature not always persistent, 

 in which case there are three or four pores between dissepiments. 

 Fenestrules on the reverse face oblong, becoming oval towards the 

 base of the polyzoarium ; on obverse face a very narrow aperture. 



Obs. This species is the common form in the Upper Silurian 



group, and tolerably abundant in the Dudley Limestone, in this 



respect occupying a corresponding position to the Fenestella plebeia, 



M'Coy, among the Carboniferous species. If the nature of Lonsdale's 



* King's Perm. Fos?. p. 37- 



Q. J. G. S. No. 142. B 



