190 THE VOYAGE OF H.M.S. CHALLENGER. 
Buch, however, clearly distinguished the essential differences between Crinoids and Cystids.’ 
The same was the case with Edward Forbes, who having given the Crinoids ordinal rank 
in 1841’ under the remarkable name “ Pinnigrada,” assigned the same position to the 
Cystids in 1848.> Von Buch seems to have considered the Blastoids as a third group of 
equal value with these two. Roemer, on the other hand, degraded the Cystidea and 
Blastoidea to the level of families or sections of the order Crinoidea, separating off the 
brachiate forms of the latter as true Crinoidea.* A few years later he proposed to call 
these by the name “ Actinoidea,” and to rank them together with Blastoids and Cystids 
as suborders of the Crinoidea.’? This term was thus employed, not in the strict sense of 
Miller’s original definition, but as co-extensive with the name ‘ Pelmatozoa,” which had 
been proposed by Leuckart four or five years previously; though Roemer appears to 
have been unacquainted with it. This was unfortunate, as the use of Leuckart’s excellent 
name in the Lethaea Geognostica would have avoided much subsequent confusion. 
In the second volume of Bronn’s “‘Thier-Reich” the Echinoderms aret hrown together 
with the Ccelenterates into the comprehensive “ Kreis” of Strahlenthiere or Aktinozoa. 
Four classes of Coelenterates are first considered, and then the Blastoidea and Crinoidea, 
for which the cumbersome names ‘“ Blastactinota” and ‘‘ Crinactinota” are proposed. 
Fortunately, however, they have not come into general use. The Cystids are thrown 
back among the Crinoids, for Bronn did not consider them as differing from the brachiate 
Crinoids to the same degree as the Blastoids. This was altogether in opposition to the 
views of Von Buch and Edward Forbes, and also to those of Roemer,’ to whom the 
peculiarities of the Blastoids and Cystids appeared so marked, ‘‘ dass sie als gleichwerthige, 
wenn auch nicht gleich umfangreiche Sectionen oder Unterordnungen den achten 
Crinoiden entgegen zu setzen sind.” Viewed by the light of later knowledge, Bronn’s 
classification was of a distinctly retrogressive nature. 
Besides the Cystids he recognised two other divisions of the Crinoidea, viz., the 
Brachiata or the Crinoidea proper, and the Costata, Miiller, the latter imcluding the 
problematical Saccosoma. eae 
The terminology employed by Bronn for the different groups of the stalked Echino- 
derms is extremely difficult to understand, and appears to contain many errors. Thus 
on pp. 193 and 421 (op. cit.), the name ‘“ Actinoidea” for the true Crinoids is attributed 
to Miiller, though it is really Roemer’s, as explained above ; while on pp. 207 and 210 the 
true Crinoids are referred to as “ Anthodiata,” in contradistinction to the other division 
1 Ueber Cystideen, Abhandl. d. k. Akad. d. Wiss. Berlin, 1845, pp. 12, 13, 17, 27. 
2 A History of British Starfishes and other Animals of the class Echinodermata, London, 1841, p. xiv. 
3 On the Cystidez of the Silurian Rocks of the British Islands, Mem. of the Geological Survey of Great Britain, and 
of the Museum of Practical Geology, 1848, vol. ii. part 2, pp. 526, 527. 
* Monographie der fossilen Crinoiden-familie der Blastoideen, und der Gattung Pentatrematites im Besondern, 
Archiv f. Naturgesch., Jahrg. xvii., Band i. pp. 387, 388. 
° Lethaea Geognostica, Bd. i., Theil 2, p. 224. 
5 Op. cit., pp. 180, 193. 7 Lethaea Geognostica, Bd. i. Theil 2, p. 224. 
