476 



MISS E. M. K. WOOD OK THE LOWEE LUDLOW [May I9OO, 



This form is abundant in certain localities, and may be merely a 

 local variety of the typical Monograptus leintwardinensis, the two 

 not being found in association. It seems to occur at a somewhat 

 lower horizon, and may possibly represent the form from which 

 M. leintwardinensis was eventually developed. 



The form figured by Dr. Perner * as Monograptus sp. from 

 Hvizdalka is probably referable to this variety. 



British Localities. — Montgomery Road ; Long Mountain 

 (various localities, such as Hose & Crown Inn, Lower Winnington, 

 etc.) ; Lake District (Tebay Gill, Bannisdale). 



Horizon. — Near the top of the Lower Ludlow Beds. 



Associate. — M. ultimus. 



(d) Group 4. Type M. uncinatus, Tullb. 



1. Thecse short broad tubes ; apertures circular, upper wall pro- 

 longed into a spinose claw. 



2. Polypary of the general type of M. colonus. 



The typical Swedish form M. uncinatus has not hitherto been 

 found in Britain, but the group which it typifies is represented 

 by two varieties. 



Monograptus uncinatus var. orbatus nov. (PI. XXV, 

 figs. 23a & 23 b.) 



Polypary from 2*54- to 5-08 cm. (1 to 2 inches) long, and 

 increasing gradually from a width of *76 mm. (-03 inch) at the 

 proximal end to a maximum width of 1-9 mm. (-08 inch) at the distal 



end, the increase being at the rate of 

 about -13 mm. (-025 inch) for each 

 theca ; somewhat irregularly curved, 

 the dorsal margin of the proximal third 

 convex, then distinctly concave, and 

 finally in the distal third of its length 

 becoming straight or slightly convex. 

 This l broken-back ' appearance (PI. 

 XXV, fig. 23 a), though less marked 

 in some specimens than in others, is 

 characteristic, and reminds one of M. 

 riccartonensis, Lapw. Virgula slightly 

 produced distally. 



Proximal Extremity. — Sicula 

 = about 1*6 mm. (-06 inch) in length, 

 and *32 mm. (-012 inch) wide at the 

 aperture, hence it is five times as long 

 as wide. Outer wall of sicula convex, 

 especially near the aperture, and with a 

 short spine. The first theca arises from 

 the sicula above the aperture, being 

 inclined to it at an angle of 30°. The 



Etudes sur les Grraptolites de Boheuie ' pt. iii, sect, b (1899) pi. xvii, fig. 14. 



Fig. 20. — M. uncinatus 



var. orbatus 



nov. 





1(1! ^ 



few* 





18 





x 



a 



b 



a=Proximal extrer 



nity,show- 



ing sicula ; f 



rom Tref- 



nant-Middletc 



wn Brook 



b= Distal thecas, f 



rom Dud- 



ley ; coll. Dr. 



Fiaser. 



