Genus Equlsctum in the Yorkshire Coal-measures. 139 



The specimen described by these author.s is a portion of a 

 stem about 4 inclics long and about 1^ inch wide at the 

 broadest part. It shows portions of" thirteen nodes bearing 

 the ciiaractcristic toothed sheath of Eqiiisetum. The chan- 

 nelling on the stem is feebly shown, but each rib ends in a 

 tooth. 



The specimens I now describe, and one of which is here 

 figured, show the fructification of an Equisetum. They 

 were collected by ]\Ir. W. Hemingway, by whom they were 

 communicated to me. 



The first example of the fossil was received a couple of 

 years ago, but the earlier specimens discovered were not well 

 preserved and their true nature was not discerned. More 

 recently I have received some fine specimens from Mr. 

 Hemingway, which reveal the true character of the fossil. 



The cones are about I inch long and a short distance above 

 the base measure yo inch across. They are rounded at the 

 base and have been attached to a thick stem, whose width 

 can be ascertained by the concave fracture where the cone 

 has separated from the stem. This " scar " shows that the 

 top of the stem must have had a thickness of -^q of an inch. 

 From about a third above its base the cone gradually narrows 

 upwards, and ends in a blunt apex about f^j of an inch wide. 

 The whole surface of the cone is covered with hexagonal 

 plates whose diameter is from j^o to ^o of an inch. In the 

 centre of these smooth plates is usually a slightly prominent 

 point. There appear to be nine transverse rows of plates in 

 the cone figured (woodcut fig. a). 



On some of the other specimens the plates of the cone show 

 three, seldom four, ridges running from the central point of 

 the plate to the margin. These I believe to be due to 

 shrinkage of the specimen before mineralization, and they do 

 not occur on the specimen figured, which is the finest 

 example I have seen. 



For comparison I place beside the drawing of the fossil a 

 figure of an immature cone of Equisetum limosum^ Sm. (from 

 which the sheath at the base has been removed), taken from 

 a photograph of a herbarium specimen that has been com- 

 pressed during drying. There is seen here in several of the 

 plates the small central elevation, similar to what has been 

 pointed out as occurring in the fossil (woodcut fig. c). Fig. d 

 shows ope of the peltate-shields of Equisetum limosum en- 

 larged. Owing to the shrinkage of the cone in drying its 

 hexagonal form is not so distinct as in the fresh state, but 

 it exliibits the central point and the slight elevation of tlie 

 margin of the peltate-shield. Fig. h gives one of the plates of 



