EXPLANATION OF THE PLATES AND WOOD-CUTS. 



from the Eifel, and we may remark, that this locality presents the most complete 

 analogy with the Devonian beds. 



Loc, Plymouth and Bradley, frequent. 

 Fig. 28. Orthoceras cylindraceum ? An imperfect specimen. We have called it the 

 same as that in the black limestone of N. Devon (PI. LIL f. 6, 7), though the 

 smooth species are so much alike that without good specimens we would not pre- 

 tend to determine positively any one. 



Loc. Newton Bushel, with Brontes Jiabellifer, Goldf. 

 Fig. 29. Orthoceras Tubicinella. Slowly tapering, ornamented with prominent trans- 

 verse oblique rings, which are crossed by numerous thread-hke ribs without inter- 

 mediate ones, giving it exactly the aspect of the recent Tubicinella Balcenarum ; 

 section circular. 



This very pretty species bears a good deal of resemblance to O. striatulum 

 (PI. LIV. f. 20), but the longitudinal ribs are much thicker and more prominent 

 than in that species ; it resembles too the O. rugosum, Flem. (Phill. I. c, PI. XXI. 

 f. 16.), but in that beautiful shell the rings are more distant, and the longitudinal 

 ribs are elevated into spines at short intervals. 



Loc. Plymouth. 

 Fig. 30. Remains of an Asaphus or Trinucleusi common at Newton Bushel. 



It is remarkable that no trace of the position of the eyes remains on the cast, 

 which is also the case with the genus Trinucleus, Murchison. 

 Fig.SX. Pelvis of Cupressocrinites'i We have seen two specimens of the pelvis in 

 the Plymouth limestone, and one of the arm of this curious animal from CoUump- 

 ton, where also large specimens of Brontes Jiabellifer occur. 



Loc. Plymouth, Collumpton, 



Plate LVIIL 



Corals from the limestones south of Dartmoor, described by Mr. Lonsdale. The 

 specimens are principally in the cabinets of Mr. Austen, Mr. Daniel Sharpe, the 

 Rev. R. Hennah, and the Woodwardian Museum, Cambridge. 

 Fig. 1, 1 a. Astrea pentagona (De Blainville, Man. d'Actinologie, p. 375). 



Cyathophyllum pentagonum (Goldfuss, Petref. p. 60, Tab. 19, f. 3.). 



Stars irregular in size and shape, but well defined, both on the weathered sur- 

 face (Fig. 1.) and in a polished section (Fig. 1 «.), the boundaries being formed by 

 zig-zag lines connecting the ends of the rays. On a weathered surface, the centre 

 of the star presents a radiated boss ; but in a polished section it consists of car- 

 bonate of lime, into which the longer rays project more or less, according to the 

 state of preservation. Rays numerous, equal in breadth and uniform in character, 

 but alternately long and short, the termination of the latter assisting to define the 

 centre of the star. From the irregularity in the shape of the star, the length of 

 the rays varies considerably. Character of the perfect terminal star not known. 



Loc. Newton Bushel, Torquay, Plymouth. 

 Fig.2. Stromatopora polyrnorpha (Goldf Petref Tab. 64, f. 8.). Form irregular, 

 mammillated or branched ; composed of concentric layers, united at irregular di- 



