1863.] 



DAY LIAS OF DORSETSHIRE. 



293 



Crania, sp. Cheinnitzia, sp. 



Gryphsea Maccullochii, Sow. Nautilus semistriatus, D' Orb. 



Avicula noTemco9ta, Brown. Ammonites fimbriatus, Sow. 



Lima, sp. margaritatus, Monff. 



Plicatula spinosa, Sow. Fragments of Crustacea. 

 Pecten aequivalvis, Sow. 



7. The Brown Sands and Sandstones. — In these, masses of fossils 

 occur, chiefly collected from the outside of the blocks of sandstone. 

 Ammonites spinatus, Brug., is now the characteristic Ammonite, and 

 with it are associated some peculiar Phasianella; and the magnificent 

 Pinna Hartmanni. I have two crushed fragments of Ammonites 

 Bechei from this zone, and one of Nautilus semistriatus, D'Orb. 



Ammonites spinatus, Brug. 

 Bechei, Sow. 



Pinna Hartmanni, Ziet. 



Goniomya rhombifera, Querist. 



Avicula, sp. 



Pecten, sp. 



Plicatula spinosa, Sow. 



Nautilus semistriatus, If Orb. 

 Belemnites, sp. 

 Phasianella, two species. 



In the 18 feet of clay over the sands I have found no fossils. 



8. The Marlstone with its Pleurotomaria-bed. — These beds amply 

 atone for the poverty of the bed beneath. Ammonites spinatus is 

 still the characteristic Ammonite, occurring here in great variety. 

 Associated with this most variable and truly Middle Lias form I have 

 obtained specimens of several Upper Lias Ammonites, such as A. 

 communis, Sow. and its several closely allied forms, A. radians, 

 Schlotheim, and even A. serpentinus, Rein. ; the first-named species, 

 though not so plentiful, is represented by far larger individuals than 

 in the Upper Lias stone itself. Beautiful as are the Ammonites 

 of this bed, the Gasteropoda are still more remarkable. They are 

 most perfectly preserved, but, owing to the character of the matrix, 

 they are very difficult of extraction. My list, as given below, 

 includes many species of Pleurotomaria and Trochus, with several of 

 Turbo, Straparollus, Phasianella, Chemnitzia, (fee. Amongst these 

 are included many of those beautiful shells, figured and described 

 by Deslongchamps and D'Orbigny, from the Middle and Upper Lias 

 of Calvados. Nor are the Conchifera much less remarkable, though 

 even fewer good specimens are obtainable. Many appear to be un- 

 described species, whilst some are forms but rarely met with ; such 

 are Sanguinolaria cuneata and S. vetusta, figured by Professor Phillips 

 from the Yorkshire coast. 



The shells and the pebbles of the conglomerate are coated with 

 Serpidce, and the water-worn stones are perforated by Lithodomi. 



Brachiopoda are also well represented. Spirifera Walcotti, Sow., 

 and S. rostrata, Schloth., occur, though rarely. Terebratula Edwardsii, 

 Dav., is common, and T. subpunctata, Dav., very fine. Several 

 other Marlstone species are represented : T. resupinata, Sow., how- 

 ever, which is common in this zone in many localities, is here alto- 

 gether absent ; T. comuta, Sow., elsewhere abundant, is here scarce, 

 being apparently replaced by its variety T. quadrifida, Lam., which 

 latter here appears also to have attained to a greater size than else- 

 where in England, thus approaching to its Continental types. Rhun- 

 ehonella serrata, Sow., rare elsewhere, is here not uncommon. 



vol. xix. — part i. x 



