MONOGRAPTUS. 423 



those of the above-mentioned species, they are shorter and broader and have rela- 

 tively larger apertural hooks ; and from M. pandits it differs in the same particulars. 



H&rizon and Localities. — Gala-Tarannon Beds (zone of M. tumculatus to zone of 

 .1/. griestoniensis). 



8. Scotland. — Buckholmside, Galashiels; Ladhope Burn; Thornylee ; Blythe 

 Water, Lauder ; Caddonfoot. Wales : Llanystwmdwy, near Criccieth ; Conway ; 

 Tarannon River, and other localities near Llanbrynmair. Lake District : Skelgill ; 

 Pull Beck. 



Associates, etc. — Mono//. Mam is a common fossil in the Tarannon beds of Wales 

 and their equivalents in S. Scotland. 



In the zone of M. turriculatus it occurs somewhat sparingly associated with 

 M. turriculatus, M. nudus, M. nodifer, M. Becld and M. de.rtrorsits ; in the zone of 

 M. crispus, it occurs in considerable abundance, with M. crispus, and M. discus, and 

 it is also found with M. griestoniensis in the zone above. 



Collections. — Geological Survey of Scotland, Fearnsides, Jones, and the 

 Authors. 



Monograptus cultellus, Tornquist. Plate XLII, figs. 9 a, b. 



1881. Monographis cultellus, Tornquist, Nagra Grapt. fran Dalarue, Geol. Foren. i Stockh. Forhandl., 



vol. v, p. 434, pi. xvii, figs. 1 a, b. 

 1883. Mo7io</raptus cultellus, Tullberg, Skaues Grapt., II, p. 30, pi. i, figs. 26, 27. 

 1892. Monograptus cultellus, Tornquist, Siljansomradets Grapt., ii, p. 17, pi. i, figs. 32, 35. 



Polypary straight with incurved proximal extremity, very short and relatively 

 broad, about mm. only in length ; widening very rapidly from "5 mm. to 

 a maximum breadth of 1 mm. Sicula conspicuous. Thecge twenty in 

 10 mm. similar to those of M. discus. 



Desertion. — The small size of the polypary and 



Fig. 285. — Mononraptv.s cuJteUus, ,-i -i ■ i , • • P .-, • ■, -> t • -\ -\ 



Tullberg. the slight incurving ot the proximal end are highly 



characteristic of this species. The polypary shows 

 a remarkably rapid increase in breadth, widening 

 conspicuously in the five or six thecas which make 

 up the total length of the polypary itself. 



The sicula measures 1*5 mm. in length, reaching 



Small specimen, showing- sicula. En- to the top of til. 2. 

 largement of PI. XLII, fig. 9 a. . . 



Affinities. — The form of the polypary suggests 

 that of a short M. colonics, but the theca? are precisely similar to those of M. discus. 

 The combination of these two characteristics renders this species easy of 

 identification. 



5G 



