478 



MISS E. M. E. WOOD ON THE LOWER LUDLOW [May 1900, 



that the thecae are of the same type as those of Monograptus unci- 

 natus, and that this should be regarded as a variety of the species 

 distinguished by the following peculiarities : — 



(1) Polypary almost straight, except for a slight dorsal curve at the 



proximal end; 



(2) Maximum width of 1*27 mm. (*05 inch) attained very gradually and 



uniformly ; 



(3) Thecae twenty-six to twenty-two in the inch (ten to nine in 1 cm.) ; 



(4) Apertural claw shorter and narrower, and form of theca resembling that 



of M. vomerinus more closely than it does that of M. riccartonensis. 



The above characters will serve to 

 distinguish it from M. uncinatus var. 

 orbatus. 



I believe that the English form is 

 identical with Jaekel's species micro- 

 poma, though I have been unable, on 

 account of the scarcity of specimens 

 and the consequent lack ot good 

 material, to investigate all those struc- 

 tural details necessary for a thoroughly 

 satisfactory identification. The German 

 specimens appear to be in a better 

 state of preservation than the English 

 examples, and Jaekel considers that the 

 apertural spine is rather of the nature 

 of a lobe than a spine proper. This 

 view coincides with my own opinion. 

 Jaekel holds that his species is identical 

 with Monograptus sp. of Heidenhain, 

 and I have therefore used Heiden- 

 hain's description to supplement his 

 own. 



The English and German specimens 

 of this variety agree in the following 

 characters : — 



Fig. 21. — M. uncinatus, 

 var. micropoma (Jcekel) 

 x5. 



m 



V J-1 



I 



B 



w 



a = Proximal extremity, with 

 sicula ; from Elton-Lud- 

 low Road. 



b «= Distal theca; from 

 Stormer Hall. 



(1) The general form of the polypary ; 



(2) The number of thecas to the inch ; 



(3) The general shape of the thecae and the nature of the aperture. 



The angle of inclination of the thecae to the axis is greater in 

 the German specimens (45° against 25° to 30°), but this may be due 

 merely to the conditions of preservation ; indeed, in the proximal 

 part of fig. 5 of Jaekel, the angle of inclination is only 30°. 

 The spine in Jaekel's figures is shorter than in the English 

 specimens. 



Foreign Localities. — Graptolithengestein at Kunzendorf; 

 doubtfully from Rostanga in Scania. 



British Localities. — Ludlow district (Elton Lane, Elton- 

 Ludlow Road, and Stormer Hall) ; Long Mountain (Lower Win- 

 nington and Garbett's Hall). 



Horizon. — In England this variety occurs in the zones of 



