TRANSACTIONS OF THE SECTIONS. 83 



determination. Owing to their fragmeutaiy condition the following species only 

 could be determined : — 



Didymogi-aptus afRnis, Nich, Diplo^-aptus dentatus, Brong, sp. 



bifidus, ILill. (=i). pristiniformis, Halt); 



geminiis, His. sp. mucronatus, Hall, 



patiilus, Hull. Climacograptus sealaris,X/»m. sp. 



The evidence aftbrded by these species was considered to be decidedly iu favour 

 of the view that these new Eamsey-Island beds were of UppeT Arenig age, and 

 therefore higher than those previously known. 



Comparing the Graptolites of the Sldddaw slates of Cumberland and the Arenig 

 roclis of Shelve with those of the Lower and Upper Arenig rocks of Kamsey Island, 

 there appeared upon the whole to be a parallel succession of species in the Shelve 

 and Ramsey-Island rocks ; while the Skiddaw series seemed to be more nearly re- 

 lated to the upper than to the lower Ramsey- Island beds ; and it was inferred that 

 the Skiddaw slates, which have hitherto been considered our oldest graptolite- 

 bearing rocks, are of more recent age than the lowest graptolitiferous rocks of St. 

 David's. 



On tlie Occurrence of numerous Sjyecies of Graptolites in the Ludlow HocJcs 

 of Shropshire. By John HopiciKsojsr, F.G.S., F.Ii.M.S.- 



Until recently only two species of Graptolites, 3Ionograptus (Graptolitkus) priodon 

 and M. culomts, were believed to occur in the Ludlow rocks of Shropshire. In 1868 

 Dr. Nicholson added to these a new species of Ptilof/rapivs, and mentioned the pre- 

 sence of an additional species of 3Ionograptvs. These had been collected by Ml". 

 Lightbody of Ludlow, who had also found a few other species in these rocks. 



In the course of an excursion of the Geologists' Association to the Silurian rocks 

 of Shropshire in July 1872, and during a subsequent visit which the author had 

 paid to Ludlow and its neighbourhood, several other species had been found, and 

 some information on the distribution of the species had been elicited. 



While, however, the number of species known to occur in the Ludlow rocks has 

 been greatly augmented by these researches, one or two forms, hitherto supposed 

 to be characteristic of one or the other division of these rocks, had not been found in 

 them. Not a single specimen of Monograpt'us priodon had been seen in the Ludlow 

 rocks, all that were found being from the "Wenlock shale ; and not a single Grap- 

 tolite had been detected in the Upper Ludlow rocks, although two species, M. co- 

 lonm and M. ^n-iodoii, had been stated to be of common occurrence in both the Lower 

 and Upper Ludlow. The Graptolites, with the exception of a species or two of the 

 Dendroidea, appeared to have died out for ever in the Aymestry limestone, in 

 which a few indeterminable fragments only have been found. 



The following species had been detemiined : — 



Hhahdojjhora, 

 Monogi'aptus bohemicus, Barr. Monograptus incurvus, sp. nov. 



eapula, sp. nov. leintwardensis, sp. nov. 



chima?ra, £arr. Nilssoni, Bcirr. 



clavicula, sp. nov. Salweyi, sp. nov. 



■ colonus, liarr. sen-a, sp. nov. 



Dendroidea. 

 Ptilograptus anglicus, Nich. Ptilograptus (ye^Dendrograp- 

 elegans, sp. nov. tus) Nicholsoni, sp. nov. 



These species were found to be restricted in their range in time, and to charac- 

 terize the same zones at distances wide apart. Some progress had been made to- 

 wards working out this interesting question ; but a more lengthened investigation 

 of the Lower Ludlow rocks in the Ludlow area was considered to be necessaiy 

 before any definite conclusion could be arrived at. 



6* 



