ON THE STOCK DALE SHALES. 



073 



Monograptus Clingaui, (Jarr. 



gregarius, Lapw. 



JNicoli, Harku. 



crenularis, Lapw, 



spiiiigerus, Nich. 



distans, Portl. 



jaculuin, Lapio. 



Rastrites urceolus, liichter, 

 hjbridus, Lajjw. 



Diplograptus tamariscus, iSVc/i. 



sinuatus, l^ich. 



Potalograptus ovaLus, Barr, 



t'oiium, His. 



Climacograptiis normalis, Lapw. 

 Favosites muUochensis, Wich. ^ 



Eth.,jmi. 

 Peltocaris aptychoides, Salt. 

 Aptycbopsis Lapworthi, Woodw. 



From the abundance oi Monograi?tus Climjani^ Carr., which usually 

 occurs in an immature condition, this band may be termed the 

 M.-Clingani Band ; it is not worthy to rank as a distinct zone. Only 

 one specimen of Monograptus gregarius has been hitherto discovered 

 in it. 



(2) The Clmgani-ha.nd passes up in the usual manner into yet 

 another band of blue muds tones, four feet six inches thick, and 

 containing a liue of calcareous nodules close to the summit, and 

 another about two thirds of the way up. This is clearly seen on 

 the path at the Lower Bridge, and at many points higher up the 

 stream, Possils are tolerably abundant, especially between the two 

 lines of calcareous nodules. We have collected : — 



Ampj-x aloniensis, n. sp. 

 Harpes angustus, n. sp. 



judex, n. sp. 



Proetus brachypjgus, n. sp. 



Phacops elegans, var. glaber. 

 Cheirurus bimucronatus, Murch. 

 var. acantbodes. 



From the occurrence upon this horizon only, and in tolerable 

 abundance, of the very interesting form of Ampyx, we name this the 

 Zone of Ampyx aloniensis. 



(3) The Ampyx-zone passes up into an extremely well-marked 

 zone of Graptolitic shales, 3 feet 6 inches in thickness. These beds 

 consist of alternating thin laminae of black, grey, dirty white, buff, 

 orange, and green shales, with some coarser bands, the surface of 

 which is marked by lozenge-shaped reticulations ; they are well 

 seen on the path at the Lower JBridge, and at one or two places 

 along the cliff at the moorland portion of the stream, especially in 

 the bend, opposite the north-eastern end of the promontory, just 

 below the Upper Eridge. They swarm with Grraptolites, and we 

 have collected from them : — 



Moaograptus spinigerus, Nich. 



discretus, Nich. 



jaculum, La;pw. 



distans, Portl. 



leptotheca, Lapw. 



Petalograptus palmeus, Barr. 



Diplograptus tamariscus, Nich, 



Hugbesii, Nich. 



modestus, Lapw. 



Climacograptus normalis, Lapw. 

 Orthoceras araneosum, Barr. 



Monograptus spinigerus, Nich., is very abundant throughout, and 

 occurs in vast abundance in the upper portion of the zone, whilst 

 Monograptus discretus, Nich., thickly covers whole slabs of the lower 

 portion of the deposit. There is no doubt that the only suitable 

 name for this band is the Zone of Monograptus spinigerus. 



(4) The M.-spinigerus zone is seen to pass up into the highest beds 



