Dr. G. J. Sinde — Organic Origin of Chert. 435 



mentaiy wings, but also in the great development of the free-edges 

 (epimera) of the terga of the abdominal segments, so marked a 

 feature in the fossil before us. (Compare Figs. 1 and 4, Plate XII.) 



The Kilmaurs specimen, however, differs from the larva of Blahera 

 atropos (Stoll), in the presence of the anterior notch of the pronotum 

 in which the head is visible ; in the larger size of its wings and the 

 ornaments on the segments of the abdomen in the living form and 

 the difference in the ornament on the pronotum. 



In the character of the neuration of the wings in the adult of 

 Blahera atropos one cannot but be struck with its resemblance to 

 the neuration of Etohlattina amongst Coal-measure forms of Blattarise. 



Seeing that there can be little doubt that we are here dealing with 

 a larval form, it may be well to place it provisionally under the 

 genus Etohlattina, and I cannot think of a more suitable specific 

 name to propose for it than that of the geologist from whose hands 

 I received it. I therefore name it Etohlattina Peachii, after that most 

 able naturalist and geologist, Mr. B. N. Peach. 



EXPLANATION OF PLATE XII. 



Fig. 1. Etohlattina Peachii, H. Woodward, sp. uov. (enlarged three times), Coal- 

 Measures, Kilmaurs, Ayrshire. 

 ,, 2. Leptohlattina exilis, H. Woodward, Coal-Measures, Coseley, near Dudley. 

 ,, 3. Blattina insignis, Goldenberg, Coal-Measures, Saarbriick, R. Prussia. 

 ,, 4. Lavva, of Blabera atropos, Stoll, Brazil, view of upper side. 

 ,, 5. The same larva seen from beneath. 



II. — On the Organic Origin of the Chert in the Carboniferous 

 Limestone Series of Ireland, and its Similarity to that in 

 THE Corresponding Strata in North Wales and Yorkshire. 



By George Jennings Hinde, Ph.D., F.G.S., etc.^ 



THE first references in any detail to the nature of the Chert in 

 Carboniferous rocks appeared in 1878,^ when Messrs. Hull and 

 Hardman published a joint paper on the subject, treating more 

 particularly of the Chert in the Upper Carboniferous Limestone of 

 Ireland. Prof. Hull gave a general description of the distribution 

 and mode of occurrence of the Chert, and a detailed notice of its 

 microscopic structure, as shown in fifteen thin sections of the rock 

 from various localities in Ireland. The author reached the conclusion 

 that the Chert is essentially a pseudomorphic rocic, consisting of 

 gelatinous silica replacing limestone of organic origin, chiefly 

 foraminiferal, crinoidal, and coralline ; the replacement was believed 

 to have taken place before the shales overlying it were deposited, 

 whilst the limestone was in a more or less plastic condition, admitting 

 the fine percolation of water holding silica in solution. The sea 

 was believed to have been largely charged with silica in solution, 



I Paper read before the British Association at Manchester. 



^ Scientific Transactions of the Eoyal Dublin Society, vol. i. n.s. 1878, 

 pp. 71-94, pi. iii. 



