ENCRINURUS MULTISEGMENTATUS. 123 



1884. Encrinurus multisegmentatus, Tornquist, Undersiikn. Siljansom. Triloljitf. (Sver. Geol. TJnder- 



sokn., Ser. C, No. 66), p. 24, pi. i, figs. 18, 19. 

 1904. Encrinurus multisegmentatus, Reed, Geol. Mag. [5], vol. i, p. 387. 



Remarks. — This species was briefly described and imperfectly figured by 

 Portlock (op. cit.). A further description, based on Russian specimens ascribed to 

 it, has more recently been given by Schmidt (op. cit., 1881). The Grirvan speci- 

 mens, which probably belong to it, are fairly complete, one from the Starfish Bed 

 showing the thorax with twelve segments attached to the pygidium, and another, 

 also from the Starfish Bed, showing a portion of the head-shield attached to five 

 thoracic rings. 



The head-shield called A mpyx (?) baccatusbj Portlock (op. cit., pi. iii, fig. 11) is 

 now considered to belong to E. 'multisegmentatus, and Schmidt's Russian example 

 (op. cit, pi. xv, figs. 19 a, b) bears a still closer resemblance to those from Grirvan 

 than does the Irish one, in the larger size but smaller number of the tubercles on 

 the glabella. The frontal marginal row of tubercles, and the coarse tuberculation 

 of the cheeks are also well seen in our specimens. The genal angle (not preserved 

 in Schmidt's specimen) is produced into a rounded spine projecting backwards and 

 slightly outwards to the level of the third thoracic ring or perhaps farther, as the 

 tip is broken off. At the base of the spine is a large tubercle, and two similar ones 

 are seen in front. The eye is situated at about the level of the middle of the 

 glabella, and is borne on an eye- stalk projecting forwards and outwards. The 

 neck-ring is narrow and is separated by a strong occipital furrow from the swollen 

 cheek, which rises nearly as high as the glabella. The glabella is pear-shaped, 

 but expands gradually towards the front, and is not contracted in the middle nor 

 specially inflated in front. It does not reach the front margin of the head-shield, 

 which is furnished with a distinct border bearing along its edge 6 — 8 large 

 tubercles. The axial furrows are deep. The tubercles on the glabella are large, 

 coarse, rounded, and of subequal size; near the base in one specimen are two rings 

 of 5 — 6 tubercles, while further forwards they are irregularly arranged. 



The thorax consists of twelve segments. The axis is of moderate width, 

 scarcely tapering at all posteriorly ; each axial ring is slightly swollen on the axial 

 furrow into a lateral node. The pleural portions are about half as wide again as 

 the axis. The inner part of each pleura is straight and horizontal ; the outer part 

 is strongly bent down, and in the posterior pleura; it is also a little bent back. 

 Each pleura consists of a narrow, slightly raised anterior rim, separated by a 

 wider, shallow rounded groove from a strongly raised, prominent rounded ridge, 

 occupying the whole posterior half of the pleura, but tapering a little towards the 

 free rounded extremity. This ridge seems to bear a few small tubercles. The 

 axial furrows are broad. 



The pygidium is triangular and acutely pointed, but not produced into a 

 mucro. The lateral lobes are bent down gently at the sides anteriorly, but more 



