NATURE 



3C5 



THURSDAY, AUGUST 4, 1881 



FOSSIL CRINOIDS 

 M^moires de la SocUW PaUontologiqtie Suisse. Mono- 



graphie des Criitoidcs Fossiles de la Suisse. Par P. de 



Loriol. (Geneve : Impiimerie Charles Schuchardt, 



1877-1879-) 

 Iconograpliia Criiwidcoriini in SIraiis Snecia Siluricis 



Fossilium. Auctore N. P. Angelin, Opus postumum 



edendum curavit Regia Academia Scientiarum Suecica. 



Cum Tabulis XXIX. (Holmias : Samson et Wallin, 



1878.) 



PROF. P. DE LORIOL of Geneva, who is so well 

 known for his researches on the fossil sea-urchins, 

 has been occupying himself for some time past with the 

 study of the fossil Crinoids. A handsome volume, con- 

 sisting of 300 pages of text and twenty-one somewhat 

 crowded quarto plates, contains the results of his work on 

 those discovered in the stratified rocks of Switzerland. 

 It originally appeared in three parts, which formed 

 portions of the volumes issued by the Pateontological 

 Society of Switzerland for the years 1877-79. 



The total number of species described by Prof, de 

 Loriol amounts to 125, of which thirty-nine are new to 

 science. The series commences with the well-known 

 " Lily-Encrinite " from the Muschelkalk, and ends with a 

 species of D'Orbigny's doubtful genus " Cotiocriiuis " 

 from the Nummulitic Eocene of Wesen. Pateozoic 

 Crinoids are, of course, conspicuous by their absence ; so 

 that Prof, de Loriol was not hampered by having to deal 

 with any obsolete system of classification. For the 

 primary divisions of the class he adopts Dujardin's modi- 

 fication of Pictet's system. This throws such very diverse 

 forms as Encrinus, Apiocriiius, and Pentacrimis into one 

 family, the Pyciiocrinides, which is especially characterised 

 by the thickness of the plates of the calyx. 



Each of these genera, however, is best regarded as the 

 type of a separate family. In fact, Pictet's " family " 

 of Pyciwcrinidcs includes nearly all the non-pateozoic 

 Crinoids or Neocrinoidea except the Comatiila, and is 

 far more comprehensive than an ordinary zoological 

 " family." 



EnoiiiHS and Apiocrintis are fairly well represented in 

 the Jurassic rocks of Switzerland. Two species of the 

 former genus are described by Prof, de Loriol, one of 

 which is new ; and there are four species of Apiocrinus^ 

 one of which is new, though founded only on the cha- 

 racters of the stem. Millericrinus and Pentacrimis, 

 however, are considerably more abundant. Thirty-three 

 species of the former are described, two being Liassic 

 and three Cretaceous ; while there are no less than forty- 

 three Pentacrimis species, six of which are Cretaceous, 

 and one from the Infra-Lias (Rhaetic). 



Most of the species are necessarily founded only on the 

 characters of isolated joints and fragments of stems, and 

 are therefore only of provisional value ; for two or more 

 joints, the markings on which differ considerably, may 

 really belong to difterent parts of the same stem. Never- 

 theless, after making allowance for these possibilities. 

 Prof, de Loriol finds a considerable number of different 

 types of stem which are confined to particular horizons. 

 Vol. XXIV. — No. 614 



They thus acquire some sfratigraphical value, and it is 

 convenient to name them, but the names can only acquire 

 a permanent value (or otherwise) when we are acquainted 

 with the calices associated with the stem-joints in ques- 

 tion. This is, unfortunately, but far too rarely possible. 



The genus "Pentacrimis'' is a large one, and it is; 

 almost necessary to separate off some of the best marked 

 varieties as distinct generic types, just as has been done 

 with Apiocrimis. Prof, de Loriol has attempted this sub- 

 division in two cases, in one of which he seems to us to 

 be fully justified, though w-e cannot say the same for the 

 other. He attempts to re-establish the genus Cainoerintis 

 of Edward Forbes, to include those species oiPentaerinus 

 in which the basals form a complete ring and cut off the 

 radials entirely from the top stem-joint. The characters 

 of the stem and of the faces of its component joints are 

 identical with those of the ordinary Pentacrimis type ; 

 and there is so much variation in the development of the 

 basals among the different Pentacrimis species, both 

 recent and fossil, that it is hardly worth while to separate 

 off one of the extreme terms of the series as a distinct 

 genus. Besides the fossil species mentioned by Prof, de 

 Loriol Cainocrimis would include the recent Pentacrimis 

 Miilkri, Oersted, from the Caribbean Sea, P. Wyville- 

 Thoinsoni horn the North Atlantic, and P. Maclearanus 

 of the CZ/rt/Av/gtv dredgings. 



The genus Balanocrintts was established by the late 

 Prof. Louis Agassiz for a crinoidal fragment that he be- 

 lieved to be a calyx with an attached stem-joint ; and he 

 described the terminal face of the latter as resembling 

 those of the stem-joints of Pentacrimis snbteres. Prof, 

 de Loriol, however, finds this fragment to be merely an 

 abnormally swollen piece of stem, with the borings of 

 some parasitic mollusc. But the stem-joints of P. snbteres 

 have rather diflferent terminal faces from those of the 

 ordinary Pentacrimis species ; and Prof de Loriol there- 

 fore proposes to retain the name Balanocrinus for this 

 and similar forms, in which only the rim of each joint-face 

 is crenulated, and not the central ends of its petaloid 

 divisions as in the ordinary Pentacrinidce. No calyx has 

 ever been found associated with stem joints of this nature 

 except perhaps that of P. Fisheri. This name was given 

 by Edward Forbes to a specimen from the Oxford clay of 

 Weymouth that was described by Baily, who did not, 

 however, say much about the stem-joints. Prof, de Loriol 

 directs the attention of English palaeontologists to this 

 subject, in the hope of finding out whether Baily's species 

 is a Balanocrinus. If it be so, the original specimen 

 would acquire additional value from its being the only 

 one with the calyx preserved. 



The well-known genus Eugeniacrinus, which is made 

 the type of a new family by Prof, de Loriol, is represented 

 in the Swiss rocks by nine species, ranging from the 

 " Oxfordien " to the " Neocomien." The curious form 

 Phylloerinus with its deeply incised radials was described 

 by d'Orbigny as a Neocomian Blastoid allied to Pentre- 

 tnitesj but it has become less interesting since Prof 

 Zittel showed it to be a near ally oi Eugeniacrimis. It 

 is represented in Switzerland by nine well-marked species, 

 which range from the Lower Oolites to the Neocomian 

 deposits. 



Comatulce are also abundant in the Swiss rocks, twelve 

 species being described by Prof, de Loriol, eleven of 



