Vol. 56.] 



FORMATION AND ITS GRAPTOLITE-FAUNA. 



469 



Yar. /3 nov. (PL XXV, fig. 15.) 



A second variety found in the Ludlow district is of interest as 

 forming a connecting-link between the typical Monograptus varians 

 and the variety next to be described, namely, M. varians var. 

 pumilus nov. It agrees with M. varians in 



(1) The general form of the polypary ; and 



(2) The shape of the thecal. 



It is distinguished from M. varians by the following characters : — 



(1) The polypary is rather longer ; 



(2) The sicula is intermediate in length between that of M. varians and 



its variety pumilus, and extends midway between the apertures of 

 the second and third theca;. 



(3) There are from thirty -six to thirty thecas in the inch (fourteen to twelve 



in 1 cm.). 



Locality. — Ludlow district (Elton Lane). 

 Horizon. — Zone of M. Nilssoni. 



Associates. — M. varians var. pumilus, M. Nilssoni, and 

 M. dubius. 



Var. pumilus nov. (PI. 

 This variety agrees with 



Fig. 16. — M. varians var, 

 pumilus nov. (x5). 



a=Proxiinal extremity; from 

 the Abberley Hills, coll. 

 Wiekham King. 



b = Proximal extremity; from 

 Elton Lane. 



c=Cast of distal thecse, show- 

 ing growth-lines. From 

 Kound Hill, Abberley ; 

 coll. Wiekham King. 



XXV, figs. 17 a & 17 b.) 



the typical M. varians in the shape of 

 the thecae. It is readily distinguished 

 from it by the following characters : — 



(1) Polypary seldom attaining a greater 



length than 12'7 mm. (-5 inch) ; 



(2) Polypary straight, except for a very 



slight dorsal curvature ; 



(3) Sicula 1-9 mm. ('075 inch) in length and 



•32 mm. (-012 inch) wide, hence 

 6 times as long as wide, extending 

 to nearly the level of the aperture 

 of the third theca. Dorsal wall of 

 sicula very straight ; 



(4) There are forty-two to thirty-six thecse 



in 1 inch (sixteen and a half to 

 fourteen and a half in 1 cm.) ; and 



(5) The thecal growth - lines are well 



marked. 



British Localities. — Ludlow 

 district (Elton Lane, Elton-Evenhay 

 Lane, Stormer Hall) ; Abberley Hills. 

 It occurs in great abundance at these 

 localities. 



Horizon. — Zones of M. Nilssoni 

 and M. scanicus. 



Associates. — M. Nilssoni, M. co- 

 lonus var. compactus, M. dubius, M. 

 varians var. (3, M. scanicus, M. chimara 

 and its variety Salweyi. 



