474 



MISS E. M. R. WOOD ON THE LOWER LUDLOW [May I9OO, 



It agrees with the typical Monograptus chimcera in : — 



(1) The character of the proximal extremity ; 



(2) The spinose nature of some of the thecse ; and 



(3) The number of thecas to the inch. 



It is distinguished by the following peculiarities : — 



(1) The form of the polypary is that of a broad M. colonus. Length 



=2'54 to 3'8 cm. (1 to 1*5 inch), and the maximum width of 

 2 - 5 mm. (-1 inch) is attained rapidly ; 



(2) All the thecae, except the first six or seven, either have very short 



blunt spines, or are destitute of them altogether. 



The foregoing description is based partly on British specimens 

 and partly on Swedish forms in the possession of Prof. Lapworth, 

 the latter being better preserved and agreeing with the British 

 forms in most particulars. 



Localities. — Ludlow district (Elton Lane, Elton-Ludlow Road). 



Horizon. — Zone of M. scanicus. 



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



Fig. 19 



M.leintwardin- 

 ensis, Hopk., from 

 Church Hill Quarry 

 (X5). 



MONOGBAPTUS LJEINTWARBINENSIS, Hopk. MS. (PI. XXV, figS. 

 21 A & 21 B.) 



1880. Monograptus leintwardinensis, Hopk. MS. Lapworth, Ann. & Mag. Nat. 

 Hist. ser. 5, vol. v, p. 149 & pi. iv, figs. 1 a-1 d. 



Polypary short, seldom exceeding 12*7 mm. (*5 inch) in length, 

 straight distally, with a slight curvature at the proximal end. Width 

 at the aperture of the first theca (exclusive of spine) = about '85 to 



1 mm. (*03 to *04 inch). Increase in 

 width gradual for the first five or six 

 thecae, until the maximum width of 

 1*6 mm. (-06 inch) is attained: Yirgula 

 generally produced somewhat beyond 

 the distal end of the polypary. 



Proximal Extremity. — Sicula. 

 conspicuous, long, and narrow. About 

 2*1 mm. (-08 inch) in length, extending 

 to midway between the aperfcires of 

 the second and third thecae. Width at 

 oP@ f !§f^ tne aperture =*38 mm. (-015 inch), so 



that the length is almost 6 times the 

 width. Aperture provided with a long 

 ventral spine, and a shorter incurved 

 dorsal one. The dcula gives origin to 

 the first theca at a distance of about 

 one-fifth of its length above the 

 aperture. 



Thecae. — Fourteen to eleven in 

 the whole polypary, giving an average 

 of thirty-eight to thirty-six thecae 

 in the inch (fifteen to fourteen in 

 1 cm.). Fairly short and narrow 



a = Enlargement of fig, 



in PI. XXV. 

 b = Specimen showing 



21 A 



dif- 

 ferent positions of the 

 thecal spines. 



