434 



BRITISH GRAPTOLITES. 



Polypary slender, very flexed, with conspicuous ventral curvature in the 

 proximal portion, 15 cm. or more in length, widening from an almost 

 thread-like initial portion to a maximum width of about 1 mm. Sicula 

 conspicuous when preserved. Thecas eight to nine in 10 mm., like that 

 of M. uncinatus var. orbatus, but more elongated. Overlap about one-third 

 the total length. 

 Description. — The polypary is strongly flexed, but the general form is variable. 

 Usually the proximal portion shows marked ventral curvature, but it may show 



double curvature like that seen in M. Nilssoni. 

 The more distal fragments have but a slight curva- 

 ture, and eventually may be practically straight. 

 Straight fragments fully 7'5 cm. in length are 

 known, so that the total length of the polypary 

 must have been considerable. 



The sicula is but rarely seen, but when preserved 

 has a length of 1*5 mm. with short virgella ; it 

 reaches up to the level of the top of th. 1, which 

 originates about one-third of the way along its 

 length. 



The thecae are usually on the concave margin ; 

 they are in most respects like those of M. uncinatus 

 var. orbatus, but are more elongated— in fact they 



Figs. 297 a — d. — Mono<iraptns sea uirus 

 Tullbersr. 





|M 



d 



a. Proximal fragment, showing sicula. 



Figured Quart. Journ. Geol. Soc, 

 vol. lvi, p. 479, fig. 22 b. Aberedw 



Hill, Buiith ; Lower imdiow Shales, bear precisely the same relation to the thecae of that 



Coll. Wood. 



b. Proximal end. Specimen on same 



slab as fig. 102 a. 



c. Distal thecae. Figured Quart. Journ. 



Geol. Soc, vol. lvi, p. 479, fig. 22 a. 



d. Distal thee* in full relief. Elton- 



Ludlow Road, Ludlow ; Lower 

 Ludlow Shales. Coll. Wood. 



species as those of M. irfonensis to those of M. priodon. 

 Affinities. — The combination of flexed polypary 

 and uncinatus type of theca serves to distinguish 

 Monog. scan icus from all other species. Straight frag- 

 ments have a superficial resemblance to M. irfonensis, 

 but there is less ogee curvature ; the thecal termination also is a smaller hook. 



Horizon and Localities. — Lower Ludlow Shales (zone of M. Nilssoni said zone of 

 M. scan ic us). 



Shropshire: Elton Lane, Ludlow; Elton-Evenhay Lane, Ludlow; Elton- 

 Ludlow Road; Long Mountain. Wales : Aberedw Hill, Buiith. Worcestershire: 

 Abberley Hills. 



Associates, etc. — Monog. scanicus occurs typically in the zone of M. scant ens, 

 associated with Monog. chimssra and M. Boemeri ; it also occurs at a lower horizon, 

 namely, in the zone of M. Nilssoni, associated with Monog. Nilssoni, M. bohemicus, 

 M. dubius, and M. varians var. pumilus. 



Collections. — Sedgwick Museum, Lapworth, and Wood. 



