REPORT ON THE CRINOIDEA. 297 
In the year 1876 a large Pentacrinus colony was discovered at Sennecey-le-Grand. 
Numerous very perfect individuals were obtained and carefully described by de Loriol.' 
He found a verticil of cirri on every joint, and described their faces as follows :-— 
“Ta surface articulaire est plane; les petales de la rosette articulaire sont fort 
étroits, et ont Tapparence de cinq petites rigoles aboutissant aux cinq angles du 
pentagone et limitées par deux petits bourrelets paralléles, plus élevés sur l'une des 
faces de l'article que sur l'autre, et couverts de tres fines crénélures.” The figure which 
he gives (pl. i. fig. 10) shows the complete correspondence of these joints with those 
of the Liassic Hxtracrinus ; and he found this correspondence ulso in the other characters 
of the type. The radials extend slightly downwards over the top stem-joints, and the 
characters of the arm-divisions are almost exactly as in Extracrinus, except that the 
main arms and the armlets which they bear are more equal in size than in the typical 
species. 
De Loriol identified this species with Pentacrinus dargniesi of Terquem and Jourdy, 
though he considered it as belonging to the same group as Hxtraerinus briareus; but 
he hesitated to adopt Austin’s genus, and he subsequently stated that there was no reason 
to do so.” 
He also pointed out that the characters of the stem-joints and cirri of Quenstedt’s 
two species Pentacrinus briareus zollerianus and Pentacrinus briareus achalmianus, both 
from the Brown Jura (Inferior Oolite), indicate their affinity to this group. In the same 
memoir he described and figured some other stem-joints presenting all the Extracrinus- 
characters from the same formation (Bajocien) of Langres, and he subsequently found 
both these types at corresponding herizons in Switzerland. Hereferred at the same time 
to the Pentacrinus nodotianus, VOrbigny, which was described by its founder as being 
“voisine du Pentacrinus briareus.” Very similar stem-joints, each bearing five 
cirri, and having crenulated linear petals, occur in the Coralline Oolite of various 
parts of Switzerland, and are described as Pentacrinus buchsgauensis by de Loriol, 
who notes their resemblance to those of Pentacrinus briareus as a point of special 
interest.” 
We may therefore, I think, consider it certain that Extracrinus extends up above 
the Lias into the Lower Jurassic rocks of the Continent, and the same is undoubtedly the 
case in England. The Great Oolite of Minchinhampton contains stem-joints with the 
same linear, crenulated petals as those of the Liassic Hxtracrinus briareus; while similar 
joints, together with arm-fragments showing the characteristic inequality of division, 
abound in the Forest Marble at Malmesbury. _ 
To the genus Extracrinus I would also refer the Pentacrinus asteriscus from the 
1 Notice sur le Pentacrinus de Sennecey-le-Grand, p. 7. Both in this work and in the Swiss Crinoids this type 
is called Pentacrinus dargniesi by de Loriol. But the plates are lettered Pentacrinus chabasi, P. de Loriol. 
2 Swiss Crinoids, p. 116. 3 Thid., pp. 153, 154. 
(ZOOL, CHALL, EXP,—PART Xxx1I,—1884.) Ti 38 
