Vol. 56.] FORMATION AND ITS GRAPTOLITE-FAUNA. 425 



(2) Description of Sections. 



(a) Elton-Lane Section (Lane running in a general easterly - 

 and-westerly direction from Elton through Evenhay Plantation to 

 Hanway Common). — This lane affords on the whole the most com- 

 plete section in the Ludlow District, especially of the Middle Shales, 

 which are here remarkably rich in graptolites. I have therefore 

 made a detailed traverse of it, collecting graptolites from every few 

 yards, and I give here a sketch-map of the locality (fig. 2, p. 426). 

 The beds dip about 30° east of south, at an angle varying from 

 15° to 18°, and the ground rises steeply in the same direction, so 

 that continuously higher beds are exposed as one ascends the slope. 

 The Wenlock Limestone at the base is well exposed in two 

 quarries, A and A' (see map), along the side of the road, west 

 of a small stream which here marks the boundary between the 

 Wenlock Limestone and the Lower Ludlow Shales. Between this 

 stream and the place where the road bifurcates (B, 120 paces), 

 small exposures of shale occur, but these are crowded with frag- 

 ments of brachiopods, corals, trilobites, etc., to the complete 

 exclusion of graptolites. There are no exposures along the left 

 road for about 145 yards beyond B, so that I have been unable to 

 obtain graptolites from the lowest parts of the Ludlow Shales 

 At the next exposure (C) graptolites are rare, but M. colonus 

 var. compactus was identified. A few yards higher up (D, 161 

 paces), however, graptolites occur in abundance, the recognizable 

 species being M. bohemicus (Barr.) very common ; M. Nilssoni 

 (Barr.) very common ; M. scanicus, Tullb. (rare) ; M. uncinatus 

 var. micropoma (Jsekel) ; M. varians var. pumilus (very common) ; 

 M. vulgaris var. (?) ; M. dubius (Suess), etc. 



At E (249 paces) M. Nilssoni, M. varians var. /3, M. varians 

 var. pumilus, M. colonus var. compactus, etc. occur. AtE (281) the 

 beds become harder and more flaggy, graptolites are less abundant 

 on the whole, occurring rather in bands. M. scanicus and 

 M. chimcera (Barr.) become the dominant forms, while M. Nils- 

 soni appears to die out gradually. At G (341) is a thin bed of 

 shale about 1 inch thick, crowded with M. varians var. pumilus 

 to the exclusion of other graptolites, while the beds immediately 

 above and below this band are comparatively barren. Just above 

 the point where the 700-foot contour crosses the road (H) 

 occur M. scanicus, M. bohemicus, M. varians var. pumilus, M. tu- 

 mescens, sp. nov., and M. chimcera. At I (405), where the Evenhay 

 Plantation commences on the right, the graptolites which were so 

 abundant in the lower beds appear to have died out almost entirely r 

 and their places are taken by M. tumescens, which occurs here in 

 great abundance. From the commencement of the wood (I) to 

 the end of the lane (L), the strata grow more and more flaggy 

 and individually thicker-bedded. The graptolites decrease in pro 

 portion as the arenaceous matter increases, so that in the highest 

 exposures there are practically none. Throughout the whole of 

 this distance M. tumescens is the prevailing species, and its only 



