INTRODUCTION. 
IX 
parts: Stem, Theca, and Brachioles. The Stem or Column is composed 
of Columnals. The Theca is composed of Basak, Badials, and Deltoids, 
along with the various elements of the pseudambulacral or subvective 
areas. The Brachioles are the small jointed processes that fringe these 
areas. The only internal organs alluded to are the Hydrospires, which 
are folds in the skeletal substance (stereom) of the radials and deltoids. 
The material in the Museum at the time of publication of the Catalogue 
of Blastoidea had accrued mostly from the following sourcesThe 
Gilbertson Collection from Lancashire and Yorkshire, noteworthy as 
containing many of G. B. Sowerby’s type-specimens, which, along with 
others in the collection, were subsequently figured by J. Phillips. 
Renewed examination of these specimens and of Gilbertson’s manuscript 
list, preserved in the Department, has resulted in the determination of 
more originals than were known to Etheridge & Carpenter. J. Rofe’s 
Collection, from Yorkshire, valuable chiefly to the morphologist. L. G. 
de Koninck’s Collection from Belgium : since this contains the holotype 
of Pentremites waterhousianus , it is possible that the types of Mesoblastus 
crenulatus and Phcenoschisma caryophyllatum are also contained in it ; 
but in the case of Blastoids it is almost impossible, without documentary 
evidence, to identify any individual specimen, unless, as in the case of 
Pentremites waterhousianus , it is distinguished by some abnormality. 
C. Wachsmuth’s Collection,, from the United States, especially Iowa : the 
specimens alluded to in the Catalogue as from the Wachsmuth Collection 
came not from this, but from the private collection of Wachsmuth & 
Springer ; they are not in the Museum. Specimens transferred from the 
Museum of Practical Geology : all foreign, especially from Spain. Many 
other Spanish specimens, with a few from elsewhere, came through 
P. H. Carpenter, and others from S. P. Pratt. The J. E. Tennant 
Collection, British and foreign. Some other collectors from whom 
specimens were obtained were :—J. Bennie (Scotland), W. Cunnington 
(chiefly Kentucky), Lord Enniskillen (Ireland), T. Rupert Jones 
(Tennessee), J”. E. Lee (Devonshire and the Eifel), J. N. Pearson 
(chiefly Alabama), L. Saemann (North America), and G. Sowerby 
(Alabama). The names of all collectors, when known, are quoted in 
the List, since they facilitate judgment as to the authenticity of the 
name and the locality, irrespective of the consideration whether the 
specimen was a gift or a purchase. 
Since the publication of the Catalogue, the chief acquisitions have been : 
some good specimens of N. American species, previously represented badly 
or not at all, in exchange from Messrs. Wachsmuth & Springer. 
Specimens from Louisiana purchased of Mr. R. R. Rowley, and 
ranking in some cases as metatypes. Eighty specimens purchased of 
b 
