426 



BRITISH GRAPTOLITES. 



Figs. 287 a — d. — Monograptus Flemingii 

 (Salter). 



b c d 



a. Proximal end, showing sicula. Enlarge- 



ment of part of PI. XLII, fig. 5 a. 



b. Thecae in proximal region, in low relief, 



showing apertural margin. Enlargement 

 of part' of PI. XLII, fig. 5 6. 



r. More distal thecae on same specimen, show- 

 ing various appearances presented by the 

 thecae. 



d. Fragment preserved in relief; part of 

 apertural margins embedded in the lime- 

 stone. Tunnel under Wren's Nest, 

 Dudley ; Wenlock Limestone. Holcroft 

 Collection, Birmingham University. 



Collections. 



-Birmingham Univ 



Affinities. — Monog. Fle)ningii is undoubtedly 

 very closely related to M. priodon and M. riecar- 

 tonensis. From M. priodon, it differs in respect 

 of its form by being more flexed, and in respect 

 of its thecas by having a more robust apertural 

 region with a rapid diminution in breadth — in 

 other words by the shorter beak-like rather than 

 hook-like termination of the thecae. From M. 

 riccartonemsis it differs similarly as respects its 

 thecae, but agrees with it in the flexure of its 

 polypary. 



Horizon and Localities. — Upper Wenlock 

 Shales (especially the zone of Gyrtog. Lund- 

 greni). 



Welsh Borders: River Irfon, Builth ; Builth 

 Bridge ; Aberedw Hill, near Builth ; Ackley 

 Lane, Long Mountain, etc. Scotland.: Ric- 

 carton Burn, etc. Worcestershire .- Wren's Nest, 

 Dudley. 



Associates, etc. — Monog. Flemingii is a 

 common fossil at the top of the zone of Gyrtog. 

 Lundgreni, where it occurs with M. dubius and 

 the zone fossil; but it makes its first appearance 

 in the zone of Gyrtog. rigidus below, 

 ersity, Lapworth, and the Authors. 



Var. primus, nom. no v. Plate XLII, figs. 6 a — d. 



1900. Monoqraptus Flemingii, var. a, Elles, Quart. Jouru. Geol. Soc, vol. lvi, p. 402, fig. 11. 



Fig. 288, 



-Monograptus Flemirigii var. 

 primus, nov. 



Proximal end, showing sicula. En- 

 largement of part of PI. XLII, fig. 

 6 b. 



In adddition to the typical species there is a 

 variety which is in some respects intermediate in 

 character between it and var. compactus. In this 

 the polypary varies from 1 — -A cm. in length, widens 

 rapidly to a maximum breadth of 2 - 5 mm., is prac- 

 tically straight in the proximal portion, and the 

 thecae vary in number from fourteen to eight in 10 

 mm. It is a straighter and shorter form widening 

 more rapidly than the typical one, individuals about 

 2 cm. in length being of commonest occurrence. 



