Vol. 56.] 



FORMATION AND ITS GRAPTOLITE-FAUNA. 



473 



Pig. 18. — M. chimgera, 

 var. Salweyi (Hopk.) 

 from Stormer Hall 

 (xS). 



But although the extreme forms of Monograptus cJiimcera and 

 M. Salweyi are readily distinguished, there are so many intermediate 



shapes linking the two together that it 

 is often impossible to separate them. 



The only other Monograptus with 

 which this variety Salweyi can be 

 confused is M. colonus, Jaekel. That 

 form belongs undoubtedly to the 

 group of M. cJiimcera, but whether it 

 should be referred to M. chimaera or 

 to its variety Salweyi is uncertain. 

 One fragment found at the Stormer 

 Hall locality, if referable to that 

 variety, must have been of abnormal 

 size. It is 25*4 mm. (1 inch) long, and 

 about 2*1 mm. (-08 inch) wide, while the 

 virgula, which is extremely broad, is 

 produced distally for 10 mm. (-4 inch). 

 The entire polypary, however, is not 

 preserved, and consequently its identi- 

 fication with M. chimeera var. Salweyi 

 is doubtful. 



Prof. Erech identifies * M. uncinatus, 

 Tullb., with M. Salweyi, but he himself 

 figures (op. cit. fig. 213) as an example 

 of M. uncinatus a fragment from Djuirod 

 (Scania), which in my opinion belongs 

 to M. leintwardinensis. I have been 

 unable to examine Tullberg's types, but I have found his drawings, 

 as respects other species, so accurate that I have no reason to regard 

 them in this case as incorrect. 



Foreign Localities. — Unknown abroad unless M. colonus, 

 Jaekel, may be referred to it, and this occurs in the Graptolithen- 

 gestein of the German Drift. 



British Localities. — It occurs in abundance at Stormer Hall 

 near Leintwardine ; it has also been found at Elton-Evenhay Lane, 

 and at Llettygynfach, south-west of the Long Mountain. 

 Horizon. — Zone of M. Nilssoni. 



Associates. — M. dubius, M. colonus var. compactus, and 

 M. varians var. a. 



a = Complete specimen, show- 

 ing sicula. 



b= Distal thecae, with long 

 curved spines. 



Yar. a nov. (PI. XXV, fig. 20.) 



This interesting form, although undoubtedly a variety of M. cJii- 

 mcera, presents peculiarities at various stages of its growth which 

 give parts of the polypary a remarkable resemblance to M. colonus, 

 or at any rate to species belonging to that group. 



1 ' Lethaea Geognostica ' vol. i, pt. iii (1897) p. 658. 



