308 ME. E. L. GILL ON KEISLEY LIMESTONE-PEBBLES [Aug. I903, 



with Platyceras verisimile, described and figured by Mr. Cowper 

 Reed 1 as a new species from the Keisley Limestone itself ; and the 

 heads of Illcenus Bowmani were of a type that was found by 

 Mr. Reed to be abundant in the Keisley Limestone, and was spoken 

 of by him under the name of I. Bowmani, var. brevicapitatus. 



Prof. Boyd Dawkins, at my request, submitted specimens of 

 these three fossils to Mr. Reed, who confirmed my identification of 

 them and the conclusion drawn from it, namely, that the pebbles 

 were in all probability derived from beds of Keisley 

 Limestone. I have since then, through the kindness of Mr. Reed 

 and the staff of the Woodwardian Museum (Cambridge), been able to 

 compare the fossils from the Peel pebbles with the series of Keisley- 

 Limestone fossils at Cambridge which formed the main portion of 

 the material for Mr. Reed's work. 



Owing to the fact that it was only possible to examine so small 

 a bulk of the limestone, the actual number of specimens of the 

 fossils found in it was by no means large, and it cannot be supposed 

 that they make any approach to representing a complete fauna of 

 the beds from which the pebbles were derived. So far as they go, 

 however, it may be said that they not only all belong to species 

 which are found in the Keisley Limestone, 2 but that they form a 

 group which would be a characteristic small selection of fossils from 

 that horizon. The following list shows all that I have obtained. 



Trilobita. 



Illmws Bowmani, Salter. The three well-preserved heads of this trilobite 

 which I have met with are all of the form described by Mr. Cowper Reed 3 

 as Illcemis Bowmani, var. brevicapitatus. In one of them the striations 

 extend with great regularity from the front-margin to the summit of the 

 glabella ; behind this point the outer test is missing, so that it is impos- 

 sible to see whether the ornamentation was continued, as seems likely, to 

 join the occipital group of lines. A small pygidium, probably belonging 

 to this species, has also been found ; but I have seen no recognizable 

 remains of any other trilobite. 



Ostracoda. 



Many pieces of the limestone contain large numbers of ostracod-tests. It is 

 not easy to be sure of any identification of these ; but the majority appear to 

 agree entirely with Prof. T. Rupert Jones's figures 4 of Primitia Maccoyii, 

 Salter, which Mr. Reed mentions as the only form abundant at Keisley. 



Brachiopoda. 



Orthis calligramma, Dalman. One small valve and part of a larger one. 

 Orthis testudinaria, Dalman. Two small shells. 



Orthis biforata, Schlotheim. One small ventral valve, which agrees externally 

 with this species. 



1 Quart. Journ. Geol. Soc. vol. liii (1897) p. 79 & pi. vi, fig. 7. 



2 See list given by Mr. Cowper Reed in Quart. Journ. Geol. Soc. vol. liii 

 (1897) p. 85. 



3 Quart. Journ. Geol. Soc. vol. lii (1896) p. 412 & pi. xx, fig. 4. 



4 Ann. & Mag. Nat. Hist. ser. 4, vol. ii (1868) p. 55 & pi. vii. 



