496 MR. 0. T. JONES ON THE HARTFELL-VALENTIAN T^OV. I909, 



Some of the fossils can be obtained in full relief in the stream- 

 section a few feet above the last band, and the observer has 

 therefore an opportunity of examining the same species in different 

 modes of preservation. The graptolites identified from this band 

 are as follows : — Rastrites capillaris, Monograptus ansulosus, 

 M. decipiens, M. involutus, M. lobiferus, M. regularis (c), M. sedg- 

 wicki (v.c), M. tenuis (v.c), Glgptograptus serratus var. barbatus, 

 61. tamariscus var. incertus, Petcdograptus palmeus, and Climaco- 

 graptus hughesi (a). Monograptus tenuis appears to be confined to 

 the upper part, where it occurs in extraordinary abundance. 



If now we enter the old quarry on the south side of the stream, 

 we find yet another and higher graptolitic band of dark-blue shales 

 of a fine smooth texture, showing faint bedding-stripes of a slightly 

 paler colour (F. 28). It passes gradually both above and below 

 into thickly-bedded blue flags, and consequently its limits are 

 indefinite, The graptolites, which are most abundant in a layer an 

 inch or two thick near the centre of the band, are preserved in full 

 relief in brown limonite and are exceedingly perfect, the specimens 

 of Monograptus sedgwicki from this locality being among the most 

 beautiful fossils in the district. It is associated with the following 

 species : — M. ansulosus, M. convolutus var., M. crenularis (?), M. 

 decipiens, M. cf. involutus (c), M. jaculum (?), M. cf. nudus (c), 

 M. cf. runcinatus, M. sedgwicki (v.c), Orthograptus cgperoides, 

 and Climacograptus hughesi (v.c.). 1 A specimen of Rastrites 

 maximus was collected from here by Mr. J). C. Evans, F.G.S., of 

 St. Clears ; and another, almost certainly referable to this species, by 

 Mr. John Pringle and myself. They occurred but a few inches 

 above the rich graptolitic band. 



The succeeding blue flags, which were worked in the quarry, 

 yielded only a few specimens of Monograptus sedgwicki, preserved 

 in very low relief in a dark substance of chitinous appearance. 



On the east side of the quarry several thin beds of tough grit 

 with dark lamina? are interbedded with pale greenish mudstones 

 (F. 29). From the grit-beds were obtained a large number of 

 graptolites, among whicli the following species were identified : — 

 Monograptus beeJci, M. gemmatus (? ), M. nodifer (?), M. nudus var. 

 variabilis, M. runcinatus, M. sedgwicki (? ), M. turricidatus (v.c), 

 and many fragments of dendroid graptolites. 



This fauna was a surprise to me, as most of the forms are distinct 

 from those of any of the underlying beds. The distance between 

 these grits and the graptolitic band on the other side of the quarry 

 is only 90 feet : yet, with the possible exception of Monograptus 



1 Miss Gr. L. Elles believes that the form referred here to Monograptus 

 sedgwicki is one to which Barrande has given the name Graptolithus halli; 

 also that the form referred to Climacograptus hughesi is probably the same 

 as the one described by Dr. H. Lapwortb under the name of Climacograptiis 

 extremiis. The specimens agree, however, with CI. hughesi in all essential 

 •characters, while they depart widely from the description of CI. extremus. 

 Further, I have been unable to satisfy myself that the first-named form is 

 specifically distinct from Monograptus sedgicicJci. 



