(JltAI'TOLITES 01' MOW YOltK. I'AUT 1 



apertural inai'gins, which are approximately perpeiidicuhu' to the axis. 

 Entire rhabdosome bristling with straight, long (1 . 4 mm) spines, four of \vhich 

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

 the middle of the rhabdosome have a hoiizontal position and those found 

 near the antisicular end are directed upwai'd. Each theca is provided 

 with at least t\vo spines, which are sitiiated on either 

 side of the aperture, and apparently also with others 

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



Portion and localities. This form is rare (only 

 four specimens having been found) in the shale at the 

 dam, belonging to the horizon with Diplograptus 

 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 i u s; and in beds at Mt Moreno, containing forms 

 of an early phase of this horizon. 



HemarlH. Fi-om the homotaxial horizon in the 

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

 viz G . f i m b r i a 1 11 s , h i n c k s i i and a r ni 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 rhabdosome; the EUergill form, how- 

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



Fig. 101 (Jlossotfrapt us 

 hysti-ix sp. nov. KhaMo- 

 some. Deep kill. x8 



Glossograptus echinatus sp. nov. 



Plate 16, figures 30-32 



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

 some of medium size, a pei-fect specimen measuring 19.5mm, wider in the 

 middle than at the ends, about 1 . 2 mm wide 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 apertural margins straight, passing obliquely to the axis of the 

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

 are approximately perpendiculai- to the axis of the rhabdosome. The sicular 



