E. ETHEEIDGE, JTJN., ON ASTKOCRINITES, 113 



limestones, probably either No, 1 or No. 2, The No. 2 limestone 

 of the Midlothian Carboniferous Limestone series is probably the 

 equivalent of the Hosie limestone of the west of Scotland. 



P.S. Since this paper was written A. ? Bennid has also been met 

 with at Cowdens Quarry, near Dumfermlino, Fife, in shale above the 

 Linn limestone, probably the equivalent of the No. 1 limestone of 

 the Midlothian Lower Carboniferous Limestone group. (Edinb. 

 March 21, 1876.) 



EXPLANATION OF PLATES XII. & XIII. 



Astrocrinites? Benniei (R. Eth. Jan.). 



Plate XII. 



Fig. 1. View of ventral surface, crushed: a, p3eudambulacra; b, arched, con- 

 vex, and crested plates ornamented with fluted tubercles (figs. 21 & 22) ; 



c, suture between b and half the succeeding forked plate (figs. 7 & 

 7 *) ; d, central ventral aperture ; e. position of the unsymmetrical 

 lobe, broken away. 



2. View of dorsal surfaoe, crushed, covered with spike-like tubercles 



(a, fig. 24) : a, apices of two of the pseudambulacra. 



3. View of dorsal surface, somewhat distorted : a, pseudambulacrum ; b, 



sutures between the forked plates c. e! \ c, adherent Foraminifer? 

 (see fig. 24, 6) ; d, small encrinite ossicle adhering by matrix; /, base 

 of the unsymmetrical lobe. 



4. Ventral surface, much weathered, a, central aperture: b, two convex 



crested plates ; //, position of the third convex crested plate, which 

 has been removed ; b", position of the unsymmetrical lobe, which has 

 also been removed; o, pseudambulacra. 



5. Ventral surface of a nearly perfect specimen : a. three spearhead plates 



projecting over the pseudambulacra (the sutures between them ard the 

 arched plates arc well shown); b, convex crested plates, ornamented 

 with the fluted tubercles (figs. 21 & 22. : c, one of the piates bounding 

 the excentric aperture (see 6, fig. 20), probably representing half one 

 of the spearhead plates a ; d, space which would be occupied by the 

 other half of this plate, with a small portion of the plate remaining 

 (see c, fig. 20 N ; e, the exceutric-aperture plate (see figs. 13 & 14, and 



d, fig. 20) : /, the projecting lip of this plate ; g, inward process of the 

 same; h, lid. or valve covering the excentric aperture with its lateral 

 digitations ; k, three pseudambulacra ; /, space which would be occu- 

 pied by the fourth. pseudambulacrum. 



6. Dorsal surface: a, sutures between the forked plates; b, b, the two 



forked plates ; <?, base of the unsymmetrical lobe. 



7. One of the forked plates, exterior view (see b, fig. 0>) : a, concavity into 



which the apex of the pseudambulacrum is received: b, crenidated 

 ridge ; c, convex halves of the forked plate. 

 7*. Interior view of the same : a, same as in fig. 7 ; b, angular shoulders. 



8. Conjoined spearhead and convex crested plate, ornamented with fluted 



tubercles, a little laterally distorted : a, spearhead plate ; b, convex 

 crested plate. 



9. Side view of the same : the dotted line in both these figures shows posi- 



tion of suture between a and b. 



10. Side view of fig. 5 : a, elongated plate, corresponding to half one of 



the forked plates . b, pseudambulacrum ; c, excentric-aperture plate, 

 side view ; d, the lip-like projection of the same. 



i2 



