182 



N. B. Dr. Inglis subsequently addressed the following 

 letter to the Secretary : — 



Halifax, March, 1844. 



My dear Sir, — I regret that, from various causes, I shall 

 not be able to attend the meeting at Sheffield, on Wednesday 

 next, but in my absence, may I request you to present to the 

 Society, for the next number of Transactions, the accompany- 

 ing lithographs, which I have had taken from an interesting 

 fossil nautilus, found in the shale of the upper of our Halifax 

 Coal beds, and of which I spoke at the Huddersfield meeting. 



I have sent, also, the fossil itself, that it may be compared 

 with the lithograph, and shall feel obliged by your taking 

 care of the fossil, as it is the property of the Halifax Literary 

 and Philosophical Society, after whose late president and 

 founder I beg to name it. 



The characteristic features of the fossil may be enumerated 

 as follows : — 



N. Rawsoni. — Discoid, shell thick and smooth ; aperture, 

 trapezoidal, being widest at its inner margin ; volutions, four 

 or five, exposed ; outer whorl, not half the diameter of the 

 shell ; umbilicus large ; strioe undulating, bend from the 

 aperture on the back ; sides with a deep, wide, concave chan- 

 nel, near the outer margin ; edges rounded; back with a 

 broad, flat groove in the middle, a smaller one running on 

 either side of this. 



The siphuncle is very near the back, as in the Ammonite, 

 but the fossil has the characteristic septa of the Nautilus. 



It was taken from the Catherine Slack Coal Beds, which lie 

 on the Halifax and Bradford old road, about a mile and a 

 half north of Halifax, (proprietor, Joseph Stocks, Esquire.) 

 The figures a c b give a good view of the deep whorls, 

 the umbilicus, the grooves upon the back, and the aperture 

 of the shell ; and the figures of the fragments c and d exhi- 

 bit the septa and the dorsal siphuncle. 



The specimens here represented are the only fossils of this 

 species hitherto discovered in this neighbourhood, and I am 

 not aware of their having been described elsewhere. 



J. T. Clay, Esq., Rastrick. JAMES INGLIS. 



