268 THE VOYAGE OF H.M.S. CHALLENGER. 
“Travailleur ” examples of this species as a new generic type Democrinus,' which is 
really, however, only a synonym of Rhizocrinus. His account of Democrinus was as 
follows :— Le Democrinus se distingue immédiatement de tous les autres genres par la 
composition de son calice formé de cing longues basales constituant 4 elles seules un 
calice en entonnoir; un sillon circulaire sépare ces cinq basales de cinq radiales rudi- 
mentaires, en forme de croissant, alternant avec elles et surmontées elles-mémes de cing 
radiales axillaires libres, rectangulaires, mobiles, sur lesquels se fixent respectivement 
cing bras, beaucoup moins larges que les radiales. Ces bras se brisent trés facilement au 
niveau de leur articulation avec les radiales axillaires qui se rabattent alors sur la votite 
du calice.” He further adds that in Rhizocrinus “les basales sont confondues et le calice 
formé en partie de radiales.” The basals of Rhizocrinus, however, are very far from being 
“confondues,” but are large and independent, as was pointed out by Pourtalés in 1868 
and 1874, and by myself in 1877 and 1882. But Perrier, unaware of this fact, was 
unfortunately misled by the erroneous descriptions of the basals as internal and concealed 
which were given by Sars and Ludwig (ante, pp. 249-251); so that when he found 
a Rhizocrinus-like form with long and well defined basals, he naturally (though 
erroneously) considered it as new to science. 
Although, however, the radials of Democrinus may be small and rudimentary 
externally, there is no reason why the calyx should consequently be considered as formed 
by the basals alone; though Perrier regards this as another character distinguishing 
Democrinus from Rhizocrinus. In one of the specimens of Rhizocrinus lofotensis which 
was figured by Sars’ the radials are quite small externally; but they have large distal 
faces for the attachment of muscles and ligaments, the inner surfaces of which form the 
funnel lodging the lower part of the ccelom. The same is undoubtedly the case with 
the radials of Democrinus, to which the movable first brachials (axillaries, Perrier) are 
attached just as in Rhizocrinus. 
It is difficult to understand why the radials of this type should be considered as 
forming part of the calyx, while those of Democrinus are excluded from it on account of 
their smaller size. On the same principle one would have to describe the cup of those 
species of Antedon in which the first radials do not appear externally, as formed by the 
centro-dorsal only ! 
Prof. Perrier describes the rudimentary radials of Democrinus as separated by a 
circular furrow from the basals below them. Buta drawing of the type which he has 
kindly sent me, shows that while the basiradial suture is marked by five strong 
elevations with intervening depressions in which the radials rest, the furrow crosses the 
radials at the level of the highest angles of the basals. This furrow is more or less 
distinct in various specimens of Rhizocrinus rawsoni (Pl. IX. fig. 3; Pl. LIT. fig. 8), as 
has been pointed out already. But it can hardly be said to “separate” the radials from 
Comptes rendus, t. xevi. p. 450. 2 Crinoides vivants, Tab. ii. fig. 44. 
