228 CATALOGUE OF THE BLASTOTDEA. 



SCHIZOBLASTUS RoFEI, E. & C. 



(PL VI. fig. 17 ; PL VIII. figs. 9-11 ; PL XVII. fig. 2.) 

 Granatocrinus Kofei, E. & C. (MS.), Ann. & Mag. Nat. Hist. 1882, vol. is. p. 239. 

 Sp. Char. Calyx small, elliptical, subglobose ; base truncate, more or less flattened, 

 with a small and moderately deep central concavity ; section obtusely pentagonal, 

 with the angles of the pentagon truncated and the sides slightly concave ; periphery 

 nearly equatorial. Basal plates very small, chiefly confined to the basal concavity, 

 but extending slightly beyond it. Radial plates very small and short, but not 

 wholly visible in a basal view ; limbs very short, and horizontally truncated above ; 

 sinuses relatively wide, parallel-sided for two thirds of their course ; radial portions 

 very short, and merely receiving the apices of the ambulacra, their margins promi- 

 nent ; radio-deltoid sutures horizontal, faintly marked as a rule ; lips small and 

 thickened, but not very prominent. Deltoid plates large, long, and triangular, con- 

 cave, with a well-marked granular median longitudinal ridge ; apices enlarged ; 

 lateral margins thickened and strongly granular. Ambulacra not projecting above 

 the edges of the sinuses; lancet-plate but slightly exposed; side plates relatively 

 large, twenty to thirty, almost transversely pyriform in shape ; outer side plates very 

 minute ; pores large, excavated in the sides of the sinuses. One hydrospire-tube. 

 Spiracles very small, appearing as eight elongated slits at the sides of the deltoids ; 

 the posterior pair confluent with the anus, which is large and oval. Ornament con- 

 sists of coarse strong granules, few in number, and arranged in rows, those along the 

 margins of the sinuses more numerous and closer together ; apices of the deltoids 

 devoid of ornament. 



Remarks. The collection contains numerous examples of this little species, 

 which we believe to be quite undescribed. We have previously referred to it as an 

 aberrant species of Granatocrinus l ; but an examination of some better-preserved 

 material than was available when our figure of the summit was drawn (PL VIII. fig. 9) 

 has led us to transfer it to Schizoblastus, and we have been confirmed in this deter- 

 mination by the discovery of another species of the genus also from the Carboniferous 

 Limestone of Ireland (PL XVI. figs. 12, 13). The latter type has been kindly lent 

 to us for comparison by Mr. W. H. Baily, F.G.S., of the Irish Geological Survey, to 

 whom we have dedicated the species. The small size of its deltoid plates readily 

 distinguishes it from S. liofei (PI. VIII. fig. 10), which in this respect resembles the 

 type of the genus, the American S. Sayi. But in both the Irish species the posterior 

 spiracles are confluent with the anus, and this is not the case in S. Sayi, which has 

 all three openings protected by a strongly arched hood. 



The coarsely granular character of the calyx is a very marked feature in *S'. Rofei, 

 a point in which it resembles some forms of Granatocrinus ellipticus (PI. VI. fig. 21), 

 and the other British species of Granatocrinus (PL IX. figs. 8-10 ; PL X. figs. 0, 7-9, 

 1 Ann. & Mag. Nat. Hist. 1882, vol. ix. p. 230. 



