Lapworth— Graptolites of Co. Down. 
135 
20; Diplograptus ciliatus , Ibid. Fig. 19; Diplograptus spinulosus, Hall. 
Diplograptus fimbriatus , Hopk. (Geol. Mag., 1872. PI. 12, fig. 8.) 
Diplograptus pinguis, Ibid. Fig. 7 ; all belong to this genus and will pro- 
bably prove to have been founded on either one or two distinct species : the 
aspect of the polypary varying to an extraordinary degree according to the 
direction in which the compression has been effected. Localities- -Coalpit Bay 
and Ballygrot. 
Genus VII. Lasiograptus. Lapworth 
S 1 * Sp. 1. Lasiograptus Harknessi. Nich. PI. 6, fig. 26. 
An examination of Nicholson’s type specimen of his Diplograptus Hark- 
nessi has convinced me that it is identical with my Lasiograptus costatus , which 
must consequently be suppressed. This species has a great range in the Moffat 
Series, passing upwards from its very lowest beds into the middle of the Hart- 
fell Shales. Occasionally a specimen is detected in which the ventral spines are 
rudimentary and do not anastomose. Locality — Carnalea. 
52. Sp. 2. Lasiograptus margaritatus Lapw, PI. 6, fig. 25. 
Polypary diprionidian, about one inch in length and about one-eighth of 
an inch in diameter, inclusive of the marginal net-work. Virgula ca- 
pillary, just visible beyond the distal margin Hydrothecse 25 to 30 to 
the inch, free, triangular in form, with long-pointed denticles which 
are developed horizontally outwards as distinct filaments to a distance 
equal to the width of the central portion of the polypary, where they 
are split up into several subordinate threads. These are united to those 
similarly derived from the hydrothecse immediately above and below, 
and thus originate a continuous series of marginal meshes completely 
surrounding the polypary. 
I11 this species the hydrothecse are of the type of those of Diplograptus 
mucronatus (Hall), and the general aspect of the polypary is essentially similar 
to that of Diplograptus limucronatus (Nich.). In Lasiograptus Harknessi the 
thecae resemple those of Climacograptus. Locality— Unknown in Ireland. 
Genus VIII. Clathrograptus. Lapworth. 
53 - Sp. 1. Clathrograptus cuneiformis. Lapw. PI. 6, fig. 27. 
The figure shows merely the skeleton framework of the polypary. In well 
