xc BRITISH GRAPTOLITES. 



Ig7g The results of the researches of Swanston among the 



Swanston & Lapworth , Graptolite-bearing Silurian rocks of co. Down, together with 



" On the Silurian a list of the Graptolites that they afford, were published in 



Eocts of Co. Down, 1876—1877. Many new localities for Graptolites in Ireland 



™ „,;„ J,- n are given, and the existence of the representatives of the 

 ' Proc. Belf . Nat. Field . 



(j lulj i Glenkiln shales, Lower and Upper Hartfell, Lower and Upper 



Birkhill (with the exception of the Rastrites maxlmus zone), 



and the Gala beds is proved. 



To Swanston' s paper there is an Appendix by Lapworth in which he figures 

 and describes, mainly from his own collections, a large number of the species 

 common to Ireland and Scotland. The majority of these were forms already 

 named, while a few new forms are described in addition. (Those marked 

 S.F. below had already been figured by Lapworth in his ' Catalogue of Western 

 Scottish Fossils,' and are here described for the first time.) The list includes : 

 (1) Rastrites peregrinus, (2) var. hybridus, (3) Monograptus triangitlatiLS, (4) 

 M. spiralis, (5) var. fimbriatus, (0) var. communis, (7) var. proteus ?, (8) M. Sedgwick!, 

 (9) M. turriculatus, (10) M. crispus, (11) M. exigmis, (12) M. Barrandei, (13) 

 M. runcinatus, (14) M. lobiferus, (15) var. pandus, (10) M. priodon, (17) 

 M. riccarionensis, (18) M. galaensis, (19) M. M'Coyi, (20) M. Hisingeri var. 

 jaculum, (21) M. ci/phus, (22) M. leptoiheca, (23) M. concinnus, (24) M. gregarius, 

 (25) M. argutus, (26) M. Sandersoni, (27) M. tenuis, (28) M. attenuatus. 



Dimorphograptus. — (29) D. Swanstoni, (30) I), elongatus. 



Cepludograptus. — (31) 0. cometa. 



Viplograptvs (in the sub-genus Gbjptograptus (0. tamariscus) Lapworth 

 believes that there is no vertical septum, the coenosarcal tube being apparently 

 undivided).— (32) P. acuminatus, i}13) P. modestus (S. F.), (34) D. sinuatus, (35) I). 

 tricornis, (3(i) P. angustif alius, (37) IK tamariscus, (^oS) P. dentatus, (39) D. Hughesi, 

 (40) D. insectiformis, (41) 1). folium, (42) D. tnmcatus, (43) D. foliaceus, (44.) 

 P. vesiculosus, (45) P. quadrimucronatas, (46) P. Whitfieldi, (47) P. (Lasiograptus?) 

 mucronatus, (48) P. (Hallograptus) bimucronatus. 



Glossograptus. — (49) G. Hincksii. 



Lasiograptus. — (50) L. margaritatus, (51) P. Earhiessi. 



Clathrograptus. — (52) G. cuneiformis (S. K.). 



Retiolites.—(b3) /.'. fibratus (54) II. perlatus ? (55) var. Daironi (50) var. 

 obesus. 



Glimacograptus.—G. scalaris, var. tectus, (50) var. normalis (57) var. rect- 

 angidaris, (58) var. caudatus, (59) var. tubulifertis (S.F.), (60) C. Scharenbergi (S.F.), 

 (61 ) 0. bicomis, (62) var. tridentatus (S.F.), (63) var.peltifer (S.F.), (64) C. codatus, 

 (65) G. Wilsoni (S.F.), (00) G. perexcavatus (S.F.), (07) G. innotafus. 



Dicranograptus. (68) P. ramosus, (09) P. Nicholsoni, (7<>) D./or?wostts, (71) P. 

 clingani, (72) P. ziczac (S.F.), (73) var. minium* (S.F.). 



