50 



FOSSIL PLANTS. 



arranged in whorls, and not spirally, as the Bracts are in most of the specimens previously 

 described. In the upper part the Bracts go off from the column nearly at right angles, 

 supporting oval Sporangia ; whilst in the lower part the Bracts are inclined downwards at 

 a considerable angle. The Sporangia all contained Macrospores, about one twenty-fifth of 

 an inch in diameter ; but, owing to compression, their characters are not well shown. 



This interesting specimen, consisting probably of not even all the lower half of the 

 original cone, was found in the Carboniferous Ash-beds at Laggan Bay, in the Isle of 

 Arran, by Mr. Russell. 



Fig. la represents the lower part of the Cone and the upper portion of the stem, to 

 which it is attached, magnified five diameters. The Leaves connected with the stem are 

 not very well defined ; but they appear to have had a verticillate arrangement. The 

 Sporangia in the lower part of the Cone were pear-shaped, and inclined downwards ; and, 

 from signs of Macrospores in the specimen, they appear to have contained those bodies, 

 which are not well shown. 



Fig. lb (magnified five diameters) represents the crushed upper portion of the speci- 

 men ; and in it are seen some indistinct Macrospores. 



This imperfect specimen is here figured and described for the purpose of showing that 

 some of these Cones have their Leaves and Scales arranged verticillately. It bears some 

 resemblance to No. 23 previously described, and to No. 30 hereinafter described (Plate 

 XIT, fig. 1). It is named provisionally Lepidostrohm ambiguus. 



§ 8. Specimen No. 28; Lepidostrobus Wuensddanus, sp. nov. PI. XI, figs. 2, ^a, 



2b, 2c. 



Specimen No. 28, PI. XI, fig. 2 (natural size), represents a slender cone, one and 

 eight tenths of an inch in length, and four tenths of an inch in breadth, found in the 

 ash-beds at Laggan Bay by Mr. Russell. A portion of the Cone next the Stem is 

 unfortunately wanting, but the specimen, on the whole, is in a more perfect condition 

 than any of those previously described. The Sporangia are of an irregular oval form, and 

 are supported by Scales or Bracts, which, in the middle of the specimen, spring from the 

 Column at right angles, show a spiral arrangement, and have their apices pointing 

 upwards nearly parallel to it. The Sporangia contain Spores of two kinds ; the upper 

 ones being filled with a granular matter, composed of small spheroidal Microspores ; 

 whilst the lower Sporangia, on each side of the column for the last four, so far as exposed, 

 had Macrospores one twentieth of an inch in diameter, with granulated outsides. In 

 each of the latter Sporangia there appears, from the evidence afibrded by the specimen, to 

 have been three Macrospores. 



Fig. 2a (magnified five diameters) represents the upper part of the Cone, showing the 

 apex and six Scales on each side of the Column, supporting Sporangia filled with fine 

 granular matter. 



