396 



BRITISH GRAPTOLITES. 



the proximal portion of tlie ])ol_vpary the tliocre are barely twice as long as wide, 

 but tlie length increases in tlic distal portion. 



Affinities. — At first sight this form appears to resemble M. colomis very 

 closely ; the polypary, liowcver, is in reality shorter and narrower, it increases 

 more uniformly in breadtli throughout its length, and the characters of tlie adnlt 

 thecEe are different. 



Horizon and LocaliiiPH. — Lower Lndlow Shales (zone of M. Nihf<oni). 

 Long Mountain District : Winnington Green ; Old Dingle Mill ; Garbett's Hall ; 

 Trefnant-Middletown Brook. Lvdioiv District : Mary Knoll ; Elton Lane. 



Associates, etc. — Mouorj. rarians seems to take the place of M. colonus in the 

 Lower Ludlow Shales of the Long Mountain District, where it occurs in some 

 abundance associated with Mono/]. Nilssoni, M. diilrius, and M. rarians Yixr.jinmilKS ; 

 it also occurs, thongh rather less commonly, in the Lndlow District at the same 

 horizon, associated with M. Nils.^oni, M. chimsern var. Salweyi, and M. diihiiis. 

 Collections. — Sedgwick Mnseum, Hopkinson, Lapworth, and the Authors. 

 Note. — Mouofj. rarians is remarkable in presenting certain local variations, and 

 on approximately the same horizon, so far as can be judged. It occurs at several 

 localities in large nnmbers in the Long Mountain District ; at some of these it is 

 small, and only the two basal thecas are retroverted at their apertures. At 

 Dingle Mill its length is normal, but so far as can be seen only one theca shows a 

 retroverted aperture ; while at Garbett's Hall it is still long but with two 

 Figs. 264 a—c.—Monograpius varians, basal tliecffi showiug the retrovcrted character. 



Again, in the Trefnant-Middletown Brook it is 

 somewhat broader than usual, and the first three 

 thecse are all retrovert. In all cases the fossils 

 seem to occur in association with M. Nils.'^oni. 



The description as given above includes Wood's 

 var. o and var. /3, which are probably inconstant 

 local varieties. 



var. pumUiti;, Wood. 



S 





iE.J 



r 



/> 



k 



\i 



m 



b 



Var. pumilus, Wood. Plate XXXIX, figs. 7 a-e. 



1900. Monnfirapfvs varians, var. ^»/iH(7(/.'!, Wood, Quart. Journ. 

 fleol. Soc, vol. Ivi, p. 469, text-fig. 10, pi. xxv, figs. 17 a, 17 b. 



While allowinsr for a certain amount of local 



variation in the species M. rarian.'<, there is one form 



a. Proximal end, showing sicula. Elton 



Lane, Ludlow ; Lower Ludlow 



Shales. Coll. Wood. 

 h. Distal theeae. Abberley Hills ; Lower 



Ludlow Shales. Coll. wickhain which, haviusf a lous^er rauofe than the typical 



King. . ' '^ ^ P -^^ 



c. Complete specimen, showing sicula spccics and otlicr morc definite characters, seems 



and thecal gi-owth lines, preserved „,... ,, , -, •in 



as a cast. Figured in part, Quart, worthy of distinction, and has been described by 



Journ. Geol. Soc, vol. Ivi, p. 409 __- -, ., „,, . ... • i i 



fig. 16c. Bound Hill, Abberley; VVood as var. jiumitus. ihis Variety IS invariably 



Lower Ludlow Shales. Coll. Wick- ^^ • • i Tir« • ^ ,^ 



ham King. Small 111 size, rarely exceeding 12 cm. m length, 



