FROM THE YOREDALE SERIES. 615 
fms. ft. in 
Main chert or “Red Beds” (fish-remains) (Harmby 
MEAG SHONE GUAEEN,) <¢:s.0a:c asconewnaesivacestcneeeennenes dads oe 0 0 
DIN TAM UMMC SLOMea ues (e150 <'s an acacinces aeedoenes sapenetereecmees since TG 
Shales: (Black: Qnarty))....ss.c.css0 chcec sere neem eet eee omer be eae 
Main or twelve-fathom limestone (Leyburn Scars)...... 10 Sam0 
BEL ween a Pa 4 SNS dole isis 0 sin a nies oiaren ote oe ORRER RS EE oe aE 0 O 
Aha OR GOTIS MNO mesa ciatiatesicr ass voca.cis aa oinaan detecone mentees 4 0 0 
Sandstones with coal 6 inches thick in Leyburn Shawl. 2 4 6 
Mate Ome nae eee ies cick oo oesecacupessacceast tate nite: 4 4 6 
Undersett limestone (fish-remains) ...................2000 Zit LG 
Eee eer cerseiulec ene Sita wanes sonsisdusd obeot eens MOREE One 4 3 0 
oye IES COMGME Meet esiclie sks c\sasicoa-eescsinvea cae tneceteoeeen 3.3 6 
FES ECM Tee ea soe cicie os an tne s oeu on sabiea'e th denen eine 4 3 0 
PRMTINAM LIMES LON Gna seaccecils occ sss scce ces sccewcvenienioncecoseeet ab 
Hameo shO my SPIES ONO mar stick sss sss ao -eresecancdesseeoneemereemeree 6 0 O 
BAL OR aM GUS NAL CS are eee cic aiascasecescavesaadeaceseeate ieee i016 
Pest One) (KOSSIMTETOUS)5s<..60.0e-sesiessaascssaneshabion soeeMene 9 4 0 
Sandstones and shales in alternate beds .................. 10 O O 
MIME CAS WIMESTONC. a. 002s. s2s..esescvnccoctiasacaccereeenael 10 4 0 
Miaestone (Gilbert Scar)......6.-...c2-sccscescenes dooniondabrod 3 0 0 
a aca classe csvciein's sieves ais ws als vais ovieielde samen edee bb por 
TPP REOMOPAING SH ALO ith overcoat a5 ojclasu sass oat oulenes osueeeenene ce) By LY) 
Rat AM EMT CSEONG) se cfeccwasanisccaevactaesdaesecccaseeeesectens ray bY) 
2185p 20) GIORIIE) Soman Odes Aone ener nee nee ean eee ee 4 0 0 
Peete ES HOWE: ele o (esi ideas sed ace cessesseasectesteuane bOI 
Alternations of shale and sandstone ...................0.00 10 3 0 
Speer MOMILNMCSUOMOR a oe cass seiner «chadeacsstliosonsedycaetelces 100 
TES PAMGNIIMOSLONC) © o cnicciccieeessnies sasiecsecadoenastoeswas jocne OF BOLO 
Limestone (thickness not proved, estimated) ............ 15 0 0 
CSV ( 2B AY Gist B80 09) DSI ec 0 0 
Limestone, thickness not known. 
The fish-remains from the Crow and Undersett limestones are 
rare both in numbers and species; nearly all those described in 
this paper have been obtained from the upper beds of the main 
limestone or “ Red Beds.” I wish to express my obligation to 
Mr. William Horne, of Leyburn, for his kindness in placing his 
large collection, the result of many years of well-directed energy 
and persistent labour, at my disposal. Nearly all the specimens 
described or figured are from his cabinet. 
It is proposed: very briefly to draw attention to one or two 
features in the character of the Yoredale series of rocks, and to 
some peculiarities of the fish-fauna contained in them, and then 
to give a detailed account of the genera and species which haye 
been determined. 
The thick-bedded massive limestone which occupies the surface 
of the county in the northern parts of Craven, attains a thickness 
varying between 600 and 1000 feet. The upper part of this 
great mass a little further north becomes intercalated with beds 
of shale, and the latter in its progress still further northward 
becomes of increasing thickness and importance, and in addi- 
tion strata of sandstone and grit also make their appearance. 
In the same localities the limestone holds a proportionately less 
important position, diminishing in thickness as the shales and 
sandstones increase. In Wensleydale the variety of alternations 
272 
