LEPIDOSTROBUS. 



57 



Fig. 2^ (magnified five diameters) represents the lower part of the Cone next the Stem, 

 and exhibits evidence of four Scales, on each side of the Column, supporting Sporangia, 

 containing Macrospores. 



Fig. 2c (magnified ten diameters) represents a single oblong-oval Sporangium, full of 

 spheroidal Microspores, from the upper part of the Cone. The Microspores are very small, 

 and cannot be separated for measurement with any degree of certainty, owing to their 

 having been converted into a bright substance resembling iron-pyrites. 



Although this Cone is the least of any of the specimens described, its Macrospores are 

 some of the largest. It has been named after Mr. Wunsch, who first discovered the true 

 nature and position of the ash-beds in the Carboniferous formation at Laggan Bay.' 



§ 9. Specimen No. 29 ; Lepidostrobus lotus, sp. nov. PI. XI, figs. 3, 3«, 3^, Sc. 



Specimen No. 29, PI. XI, fig. 3 (natural size), represents a stout Cone, of an oval form, 

 nearly two inches in length by seven tenths of an inch in breadth in its middle, from the 

 ash-beds of Laggan Bay ; also found by Mr. Russell. This is by far the most robust Cone 

 that has come under my notice. It was covered by strong Scales ; each Bract having a 

 thick median rib, and taking nearly a vertical direction, as shown in the upper portion of 

 the specimen. In its middle and lower portions the specimen has lost its Bracts, and 

 affords evidence, although not so well marked as in the specimen last described, of two 

 kinds of Sporangia ; the upper ones exposed being pear-shaped, and containing apparently 

 Microspores ; and the lower ones which slope downwards have irregularly discoidal bodies 

 like Macrospores. 



Fig. 3 a (magnified five diameters) shows the upper portion of the Cone and its stout, 

 ribbed Scales. 



Fig. 3 b (magnified five diameters) shows the lower part of the Cone with its Sporangia, 

 and Scales inclining downwards, and some bodies resembling Macrospores. 



Fig. 3 c (magnified fifteen diameters) shows a pear-shaped Sporangium, from the 

 upper part of the Cone, filled with small granular bodies resembling Microspores. 



The three specimens last described are, as previously stated, from the trap-ash of 

 Laggan Bay, the same deposit as that from which the beautiful stems of Sigillaria, Lepi- 

 dodendron, Halonia, AiithoUthes, and other Coal Plants discovered by ]Mr. Wunsch, of 

 Glasgow, were obtained. The ash enveloping the stems is som^etimes nearly as hard as 

 greenstone, and at other times quite soft and pulverulent. It is of a greyish colour? 

 contains small bright pieces of iron-pyrites, and is intersected by narrow veins of common 

 and fibrous carbonate of lime : the mass effervesces when treated with hydrochloric acid. 

 By the kindness of Mr.Wiinsch, I am enabled to give the chemical composition of this ash. 

 ' 'Transact. Geol. Society of Glasgow,' vol. ii, p. 97. 



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