926 
MR. P. H. CARPENTER ON A NEW 
idea that the little specimen obtained from a depth of 2,325 fathoms, at Station 223 
in the east Pacific, may, perhaps, be related to the former genus. Sir Wyville 
Thomson'" spoke of it as Hyocrinus bethellianus (?), with the remark, “ It is certainly 
in many respects very unlike the adult H. bethellianus, but it may possibly turn 
out to be the young of that species.” No figure of it is to be found either in the 
“Atlantic ” or in any of the numerous plates which were drawn at Edinburgh under 
Sir Wyville’s direction, and it is to be feared that this “beautiful little thing” has 
been mislaid, as Mr. Murray has been unable to discover it among the material 
which was in Sir Wyville’s hands at the time of his death. 
The discovery of Thaumatocrinus restores the numerical equality between the living 
genera of Comatulce and of stalked Crinoids, and raises their joint total to twelve. 
Species of every genus, except Holopus, have been obtained by the various British 
expeditions for deep-sea exploration, as shown in the following table :— 
Family. 
Genera. 
Number of 
species 
obtained. 
Remarks. 
r 
Antedon, Erem . 
83 
Seven obtained by the “Porcu- 
pine” and the “ Triton.” The 
rest by the “ Challeng’er.” 
Actinometra, Mull . 
52 
“ Challenger.” One by the 
Comatulidce . . < 
[“ Porcupine.” 
Promachocrinus, F.LL.O. 
3 
V 
Eudiocrinus, P.H.C . 
3 
55 
Atelecrinus, P.H.C. 
2 
55 
Thaumatocrinus , P.H.C . 
1 
55 
r 
Pentacrinus, Miller . 
5 
One obtained by the “ Porcu- 
pineone species doubtful, 
Pentacrinidce . •< 
perhaps representing a new 
genus. 
Metacrinus Wt. Th., and P.H.C. 
10 
One founded on stem fragments 
i 
only. 
r 
Phizocrinus, Sars . 
2 
“ Challenger” and “Porcupine.” 
Bourgueticrinidce < 
Bathycrinus , Wt. Th . 
3 
One obtained by the “ Porcu- 
pine.” 
Hyocrinidce . 
Hyocrinus, Wt. Th. . . 
1 
Besides one doubtful young 
specimen. 
General considerations. 
The peculiarities of Reteocrinus, as well as of Thaumatocrinus, have suggested 
certain morphological considerations bearing on the various classifications of the 
Rhodocrinidce that have hitherto been proposed. 
One cannot help wondering where the circular commissure of Reteocrinus was 
situated. In ordinary Crinoids with directly contiguous radials, each of them is 
traversed by a portion of the circular canal in which the commissure is lodged. But 
* “Notice of New Living Crinoids belonging to the Apiocrinidce." Journ. Linn. Soc. Zool., vol. xiii., 
p. 55. 
