Part of Gloucestershire and Somersetshire. 329 



specimen be rubbed down only to the smooth part of the shelly a deceptive 

 appearance sometimes arises^ from the annuli near the pointed extremity, 

 showing divisions like septa : these^ however, vanish on continuing the abra- 

 sion into the interior of the cone. Mr. Miller considers them as forming a 

 new genus, following the imperforate dentalia comprised in the genus Caecum. 



Of bivalves we meet with various species of anomites, terebratulites, spi- 

 riferites, and productites, some of the species agreeing with remains found 

 in the carboniferous limestone, while others are wholly different ; also casts 

 resembling mytilites^ including several species depicted by Baron Von Schlo- 

 theim (Nachtrdge zur Petrefactenkunde), as derived from the transition lime- 

 stone of the Continent, and principally from that of the Hartz, the Eif- 

 felgebirge, the Duchy of Berg, and from Gothland : e. g. Terebratulites 

 priscus, T. striatulus, T. lacunosus, T. elongatus, T. intermedins (a spirifer). 

 Those casts also, derived from terebratulse and anomiae, and known by the 

 name of hysterolites, are common. Some of them agree closely with those 

 found by Messrs. William Phillips and S. Woods near Snowdon, fig. 4, 5, 6, 

 and 10. of the Plate annexed to the paper of those gentlemen on the geology 

 of Snowdon and its vicinity *. 



The coralloid remains are numerous, being referable to the genera Caryo- 

 phillia, Turbinolia, Favosites, Astrea, Madrepora, Cellepora, Millepora, Flus- 

 tra, Retepora, and Tubipora. Of the Tubipora catenulata, however, which 

 appears in some measure characteristic of the later portion of the transition 

 series, and which occurs not unfrequently in the north-west of Gloucester- 

 shire and in Herefordshire, only one specimen has been met with, which was 

 found by the Rev. Mr. Halifax, Vicar of Standish, adjacent to the Horsley 

 trap quarry. 



Crinoidal remains also are not uncommon, derived principally from cyatho- 

 crinites, but apparently also in part from actinocrinites. 



Of the organic remains, now enumerated, the sandstone sometimes retains 

 only the empty impression ; more frequently it exhibits them as casts, com- 

 posed of sandstone, hornstone, carbonate of lime (the latter not unfrequently 

 possessing the nacreous lustre), bro\vn-spar, oxide of iron, the substance of 

 slate clay, and even, though more rarely, of sulphate of strontian. These casts 

 represent either the general form, or the external or internal surface merely. 

 In the limestone, they sometimes consist of calcareous spar, more rarely of 

 brown-spar ; in the slate clay of carbonate of lime, or oxide of iron ; and in the 

 marly clay of carbonate of lime. These remains, however, as before stated, 



* Annals of Philosophy, Dec. 1822. 



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