(iUAI'TOLITKS 01' XinV YOltK. PAUT 1 725 



apertiiral inai'gins, ^^•llicll are approximately pei-peiidicului' to the axis. 

 Entire rliabdosome Ijristling with straight, long (1 . 4mni) spines, four of ^vhic]l 

 are placed at the sicular end and directed parallel to the axis, while those in 

 the middle of the I'habdosome have a horizontal position and those found 

 neai- the antisicular end are directed upward. Each theca is provided 

 Avith at least tA\o spines, which are situated on either 

 side of the aperture, and apparently also with others 

 on the lateral faces or the outer margin of the thecae. 

 Position (i/xl localities. This form is rare (only 

 four specimens having been found) in the shale at the 

 dam, belonging to the horizon with Dipl ogr a}) t u s 

 d e n t a t u s and C 1 i m a c o g r a p t u s ? a n t e n - 

 n ar 1 u s : and in beds at Mt Moreno, containing forms 



„ , , <• ;i • 1 • Fig. 101 Glossograptus 



ot an early phase ot this horizon. hystrix sp. nov. Khabdo- 



^ some. Deep kill. x8 



Iiemarl>i. Erom the homotaxial horizon in the 

 EUergill beds in England not less than tliree species have become known, 

 viz G . f i m b r i a t u s , h i n c k s i i and a r m a t u s . With the last of 

 these, the form here described possesses the most similarity, both agreeing 

 in the dimensions and shape of the rliabdosome; the EUergill form, how- 

 ever, has feAver and longer spines, which are reflexed. 



Glossograptus echinatus sp. nov. 



Plate 16, figures 30-32 



Description. Primary disk, nema and sicula not observed. Rhabdo- 

 some of medium size, a perfect specimen measuring 19. 5 mm, wider in the 

 middle than at the ends, about 1 . 2 mm Avide at the sicular end, 3 mm in 

 the middle (excluding the spines) and 2 . 2 at the antisicular end. Thecae, 

 narrow tubes numbering 12 in 10 mm, inclined at 15°, three times as long 

 as wide, in contact about one half of their length ; their outer margins con- 

 cave; their a2:)ertural margins straight, passing obliquely to the axis of the 

 thecae; their outer margins protracted into stout s))ines (1 .5 mm long), which 

 are ap[)roxiniately perpendiculai- to the axis of the rliabdosome. The sicular 



