Vol. 56.] FORMATION AND ITS GRAPTOLIrE- FAUNA. 461 



the base of the sicula, being inclined to it at an angle of 25° 

 approximately. 



Thecae. — Twenty-three to twenty in 1 inch (nine or eight in 

 1 cm.), and inclined to the polypary at an angle of 25° to 35°. 

 Thecae characterized by long and flexnous walls which bend 

 inward so as to be almost at right angles to the virgula. Adult 

 thecae 3 mm. (*12 inch) long and 4| times as long as wide, over- 

 lapping for a third to a half of their length. Aperture concave, 

 apparently oblique to the direction of the thecae : it has a sharp 

 denticle which is curved downward, but no spine. From Holm's 

 figures it appears that the apertures are round or slightly oval. 



Monograptus gotlandicus is allied to M. dubius 



(1) In the character of its proximal extremity ; and 



(2) In the number of thecaa ; 



but is distinguished from it by 



(1) The greater width of the polypary ; 



(2) The greater length of the thecas, and the relative proportions of their 



length to their width. 



The English form is sufficiently similar to the Swedish and 

 Bohemian forms to make it clear that they are at any rate closely 

 allied. The English graptolite appears to differ somewhat in the 

 amount of overlap of its thecae, this being greater than that measured 

 by Holm (one-fifth), but not much more than appears from his 

 figures. The angle of inclination of the thecae is somewhat less, 

 too, in the English specimens. 



A specimen now in the Prague Museum from Colonie Krejci, of 

 which I took a drawing in Bohemia, is very similar in shape to the 

 English specimen. 



Foreign Localities. — Bohemia (Koneprus and Colonie 

 Krejci?) ; Gotland (Pterijgotus-beds near Visby). 



British Localit y . — Only one specimen has been found hitherto , 

 It was obtained by Prof. Watts from the Old Dingle Mill in the 

 Long Mountain district, and is now in his collection. 



Horizon. — Zone of M. Nilssoni. 



Associate s. — M. Nilssoni and M. varians. 



Monograptus ULTiMus, Perner. (PI. XXV, figs. 9 a & 9 b.) 



1899. Monograptus ultimus, Perner, ' Etudes sur les Graptolites de Boheme ' pt. iii, 

 sect, b, pp. 13-14, text-figs. 14 a-b & pi. xvi, figs. 4, 5, 11 a-b. 



The collection of graptolites from the Long Mountain, made by 

 Prof. Watts, contains a few indifferently-preserved specimens of 

 a small graptolite which is almost certainly the British repre- 

 sentative of the Bohemian species M. ultimus, Perner. The English 

 specimens are not sufficiently perfect for complete description, so 

 that the following account is drawn mainly from Dr. Perner's 

 original diagnosis andjrom my own drawings of some Bohemian 

 specimens from Xosor presented to Prof. Lapworth by Dr. Perner. 

 A few specimens of this species from the Lake District are to be 

 found in the Natural History Museum, South Kensingion. 



Q. J. G. S. No. 222. 2 1 



