Correspondence — John Leckenhy. 135 



the Forest Marble reposes. The quarries have been excavated about 

 15 feet below the surface, and are composed of 4 feet soil and moved 

 rock ; then one bed, 3 to 4 feet thick, of exceedingly hard stone, the 

 surface of which is flat, and on it large oyster-shells ; next, three 

 beds of stone ; and lastly, a coral bed of about 4 feet in thickness. 

 The coral bed has been disturbed, but in its recent state must have 

 been a beautiful sight, from the number, variety, and beauty of forms 

 and colours. I have already had upwards of 40 species brought me, 

 and such as might supply materials for a complete local coral history. 

 After the depression of the reef below the warm surf of the Oolitic 

 Sea, it was flooded with Oolitic matter, and the corals have to be 

 extracted from the mass, and much work required to clean them, 

 and specimen after specimen examined, before the characteristic 

 form of the species can be determined. I have already sixteen species 

 whose growth was by stems, varying from 3 to 60 on an inch square 

 of surface ; the calices on which number from 40 to 140 on an inch ; 

 ten that are superficial corals, and once formed the coats of moUusks, 

 the body of which has been decomposed, and a cavity left, more or 

 less filled with crystals of carbonate of lime ; I have also twelve 

 corals which formed a solid mass of coral marble, on which life 

 existed only on the surface ; and four that show a growth in bands 

 of coral marble ; one of these retains its purple colour. The reef 

 formed by these corals must have extended many miles ; upon it was 

 drifted fruits, as nuts arid stems, and after its depression a great 

 variety of univalves, bivalves, saurian vertebrse, and eggs, and teeth, 

 and teeth of fish, and portions of crabs. Although I have known 

 one of the quarries for many years, yet at most I only obtained three 

 or four corals from it ; but now that I depend on workmen who 

 break up the bed, it is impossible to say how many more new species 

 may be brought to me. Thos. C. Brown. 



Further Barton, Cibencestek, 

 Gtli Januari/, 1873. 



THE OLDEST KNOWN BEITISH TRIGONIA.i 

 Sir, — Having read some time ago, Mr. Ealph Tate's notice about 

 the oldest known species of Trigonia, in the Geological Magazine 

 for July last (see p. 306), and the reference to a specimen from 

 Marske (not Maroke, as there printed in error) , in the York Museum, 

 I desire to say that the latter is not from the Marlstone at all, but is 

 an undoubted Inferior Oolite Fossil, the matrix being in all respects 

 similar lithologically to the Dogger of the Peak, .near Scarborough. 



This leads me to doubt the whole affair, and to contend for the 

 ancestral honour so long awarded to Trigonia literata (or littorata ?) 

 of the Upper Lias. John Leckenby. 



Scarborough, January 18, 1872. 



PRINCIPAL DAWSON AND OTHERS ON MORAINES. 

 Sir, — As the reviewer of Dr. Dawson's Post-Pliocene Geology of 

 Canada in your January Number scarcely did justice to the author on 

 some points, you would oblige by finding space for a few remarks. 



' This letter was accidentally omitted last month.— Edit. Geol. Mao. 



