140 
Lapworth— Graptolites of Co. Down. 
interspaces are more oblique than in the Scottish forms. Locality— Coalpit 
Bay and Ballygrot. 
69. Sp. 5. Climacograptus Wtlsoni. Lapw. PI. 6, fig. 40. (Catl. Western 
Scottish Fossils, 1876. PI. 2, fig. 46.) 
Polypary two to four inches in length and one eighth of an inch in 
maximum diameter; proximal end abrupt, furnished with two short 
horizontal radicular processes. Septum direct. Virgula stout, distally 
prolonged for a distance nearly equal to the length of the polypary ; 
and supporting proximally a large elliptical vesicle. Hydrothecae 16 
to 20 to the inch ; short, square, perpendicular ; excavation shallow, 
horizontal. 
Closely allied to the foregoing and following species— Locality— Unknown in 
Ireland. 
70. Sp. 6. Climacograptus per-excavatus. Lapw. PI. 6, fig. 35. 
Polypary one and a half inches in length, and about one eighth of an inch 
in breadth ; margins parallel till close upon the proximal extremity which is 
broadly rounded off, and ornamented with three short, stiff, proximal spines. 
Virgula distally prolonged. Hydrothecse 28 to 36 to the inch, with inclined 
partition walls; excavations wide and deep, occupying more than half the 
ventral margin of the polypary, and from one-fourth to one third of its trans- 
verse diameter. Horizon— Glenkiln shales. Localities in Scotland— Craig- 
michan, Glenkiln, Leadhills. In Ireland— at Ballygrot and Coalpit Bay. 
A most prolific species, it occurs in great abundance at the localities cited. 
71. Sp. 7. Climacograptus innotatus. Nich. PI. 6, fig. 37. Locality— 
Coalpit Bay. 
Genus XI. Dicranograptus. Hall. (Grapt. Quebec Group, p. 1 1 2. ) 
72. Sp. 1. Dicranograptus ramosus. PI. 7 > fig- *• 
The earlier or Llandeilo examples of this and the following species are re- 
markably spinose. As we ascend in the series of beds the spines seem to become 
shorter and less conspicuous. In the highest beds where these species are 
known they are destitute of spines. Localities— Crawfordsburn, Ballygrot, and 
Craigavad. 
