WITH LIST OF SPECIMENS. 
15 
Meek & A. H. Worthen, 1866, Rep. Geol. Surv. Illinois, ii, p. 276, pi. xx, 
f. 1. Heteroblastus ? cornutus (Meek & Worthen) : R. Etheridge fil. & 
P 0 H. Carpenter, 1886, Cat. Blastoidea Brit. Mus. p. 256. 
Heteroblastus Cumberland!, R. Etheridge fil. & P. H. Carpenter, 
1886, Cat. Blastoidea Brit. Mus. p. 257, pi. vi, ff. 1-6. 
Heteroblastus Cumberlandi, R. Etheridge fil. & P. H. Carpenter, 1886, 
Cat. Blastoidea Brit. Mus. pp. 256, 257. C. Lower Carboniferous, 
Yoredale Shales : Gunnerton Burn, Hexham, Northumberland, 
England. [E. 665.] Six fragments, not figured, but forming part 
of type-material. 
Heteroblastus Cumberlandi, R. Etheridge fil. & P. H. Carpenter, 1886, 
Cat. Blastoidea Brit. Mus. pp. 107, 256, 257, pi. vi, f. 4. C. Lower 
Carboniferous, Yoredale Shales: Gunnerton Burn, Hexham, North¬ 
umberland, England. [E. 8075.] Presented by P. H. Carpenter. 
A deltoid, part of type-material. 
Heteroblastus cumberlandi , R. Etheridge fil. & P. H. Carpenter, 1886, 
Cat. Blastoidea Brit. Mus. pp. 256, 257, pi. vi, f. 5. C. Lower 
Carboniferous, Yoredale Shales : Gunnerton Burn, Hexham, North¬ 
umberland, England. [E. 8076.] Presented by P. H. Carpenter. 
Anal deltoid, part of type-material. 
Heteroblastus cumberlandi, R. Etheridge fil. & P. H. Carpenter, 1886, 
Cat. Blastoidea Brit. Mus. p. 257, pi. vi, f. 6. C. Lower Carboni¬ 
ferous (Yoredale Shales) : Gunnerton Burn, Hexham, Northumber¬ 
land, England. [E. 8077.] Presented by P. H. Carpenter. A radial, 
part of type-material. 
HETEROSCHISMA, C. Wachsmuth, 1883, Rep. Geol. Surv. 
Illinois, vii, p. 352. Type-species— H. gracile. Made syn. of Co¬ 
daster, R. Etheridge fil. & P. H. Carpenter, 1886, Cat. Blastoidea 
Brit. Mus. pp. 33, 263. 
Heteroschisma alternatum (Lyon): C. Wachsmuth, 1883: v. 
Codaster alternatus. 
Heteroschisma alternatum, var. elongatum, C. Wachsmuth, 1883 : 
v. Codaster alternatus, var. elongatus. 
Heteroschisma gracile, C. Wachsmuth, 1883: v. Codaster 
gracilis. 
MESOBLASTUS, R, Etheridge fil. & P. H. Carpenter, 1886, Cat. 
Blastoidea Brit. Mus. p. 181. Type-species— M. crenulatus. 
Mesoblastus angulatus. Pentatrematites angulata , G. B. Sowerby, 
July 1828, Zool. Journ. iv, p. 89 ; and 1834, Zool. Journ. v, Suppl.-pl. 
xxxiii, f. 1. Pentremites angulatus , “ Gilb.” : J. Phillips, 1836, Geol. 
Yorksh. ii, p. 207, pi. iii, f. 13. Orbiiremites angulatus ? (Gilb.) : T. & 
T. Austin, 1842, Ann. Mag. Nat. Hist. (1) x, p. 111. Mesoblastus 
