﻿part 1] 



A NEW SPECIES OF EDESTUS. 



5 



representing an extremely generalized species of JEdestus. It 

 dirfers from all known forms, not only in the shape and proportions 

 of the root, hut also in the shape of the crown and the significant 

 flutings and faint lateral ridge at its "base. It represents, in fact, a 

 very distinct species, which may be appropriately named IS d est lis 

 newtoni, after Mr. B. T. Newton, F.R.S., who first recorded the 

 ■occurrence of JEdestus in British Carboniferous rocks. 1 



EXPLANATION OP PLATE I. 



Mdestus newtoni, sp. nov. ; anterior ends of cartilages of jaw (c), median 

 symphysial dentition (s), a detached symphysial tooth (t), and small 

 scattered Orodont teeth (o). — Millstone Grit ; Brockholes, near 

 Huddersfield, Yorkshire. (Museum of Practical Geology, London.) 



[Pigs. 1-6 are two-thirds of the natural size, figs. 7-10 are twice the 

 natural size.] 



Pig'. 1. The whole fossil. to=worn surface on edge of tooth. 



2. Anterior end of symphysial dentition, lower view. 



3. Front view of the same. 



4. "Vertical transverse section of root of third tooth of the same. 

 Pigs. 5 & 6. Transverse sections of second and eighth teeth of the same. 

 Pig. 7. Serrations of the border of the eighth tooth. 



8. Left half of an elongated Orodont tooth (Campodus), front view. 



9. Elevated Orodont tooth (Campodus), front view ; and (9 a) upper 



view. 



10. Elevated Orodont tooth (Campodus), back view. 



Appendix. — Note on the Well-section at Rock Mills and 

 the Fauna associated with JEdestus. By John Pjbingle, 

 F.G.S. 



The well at Rock Mills (Messrs. Joseph Sykes & Co.) is situated 

 in the mill-grounds in the valley of the River Holme at Brock- 

 holes, about 4 miles south of Huddersfield. According to the 

 Geological Survey-map (Quarter-Sheet 88 S.E.), the alluvium in 

 the valley at this point rests on shales which underlie the Rough 

 Rock, the uppermost member of the Millstone Grit. The shales 

 appear to vary considerably in thickness in this district. Green 2 

 states that 100 feet of shales are present between the Rough 

 Rock and Grit A about Holmfirth, which lies 2 miles south of 

 Brockholes ; while on Holestone Moor, west of Huddersfield, he 

 estimates that they are 200 feet thick between the same horizons. 

 Spencer 3 has shown that in the district embraced in the next 

 sheet to the north (Quarter-Sheet 88 N.E.) the shales contain a 

 marine fauna ; and the discovery of JEdestus should stimulate the 

 efforts of the local geologists to further work on this horizon. 



1 E. T. Newton, ' On the Occurrence of Edestus in the Coal-Measures of 

 Britain ' Q. J. G. S. vol. lx (1904) pp. 1-8 & pi. i. 



2 A. H. Green & others, ' The Geology of the Yorkshire Coalfield ' Mem. 

 Geol. Surv. 1878, p. 59. 



3 J. Spencer, ' Additional Notes on the Millstone Grit of the Parish of 

 Halifax' Trans. Manchester Geol. Soc. vol. xiii (1873-74) p. 109. 



