INTRODUCTIOX. 5 



number of collectors to search for them in England, where the most beautiful and perfect 

 specimens have always been found, and their admirable condition in that country readily 

 caused the impression that they must be Articulata to gain ground. We learn from 

 Dr. Shaw, Lister's successor in O.xford, that he took them for a caterpillar (eruca), and 

 Ch. Lyttleton, who laid new specimens before the Royal Society of London, coincides in this 

 view ; Ch. Mortimer, on the other hand, on an occasion of some new specimens of the 

 Dudley fossil (as the Trilobites were usually called in England, from the principal locality 

 where they were found) having been sent by Dr. Pocock, expressed the opinion that they 

 appeared to correspond most with the Monoctdus apus, Linn., shortly before described by 

 J. Th. Klein, in the ' Transactions of the Royal Society' (vol. xl, p. 150). As Klein had given 

 the name of Scolopendra aqualka scutata to this animal, Mortimer proposed the designation of 

 ScoJopendrm aquaticcB scutata oßne animal petrifcatiat/, which, however, even on account of its 

 length, could not meet with any great approbation. The next English author on the 

 Trilobites, Emanuel Mendez Da Costa, endeavoured therefore to find a better name, and 

 on again laying a beautifully preserved specimen before the Royal Society, he declared 

 it not only to be a crustaceous animal, but also to be one nearly related to the sea-louse, and 

 he called it Pediculus mariniis major trilobus. This name of sea-louse was then employed to 

 designate several of the larger Isojwdes, which live on fishes as parasites, and from amongst 

 which Linnaeus constituted his genus Oniscus. Linnaeus, whose system and reform of the 

 science just then began to be appreciated, had consulted with Mendez Da Costa respecting 

 the Trilobites in the same year, and designated all the species belonging to it as modifications 

 of his Entoniolithm paradoxus, deciding himself in favour of their near affinity to Monoculim 

 npus. This view of the great naturalist, which is expressed in all the editions of the 

 ' Systema Naturae,' certainly ought to have led those who knew little more of the subject 

 than the fragments lying before them to a correct conception of the afiinity ; but their 

 very ignorance of the points of comparison made them overlook it. Several authorities now 

 again declared in favour of the afiinity to the Mvllasca ; but the French observer Guettard 

 correctly enumerated the Trilobites of Angers among the Crustacea, designating them as 

 allied to the genus Oniscus of Linnaeus. This author was, however, perfectly unacquainted with 

 Linnaeus, and equally so with the German writers, who also have never taken any notice 

 of him. The next writer on the subject, Father Joseph Torrnbia, having been a native of 

 Spain, where the sciences were in a dormant state, I shall not lay any great stress upon his 

 opinion, but he at first correctly described the Trilobites as crustaceous animals, although 

 subsequently, misled by the inspection of Rumphius's figure of the Liiiice marina {Chiton 

 aculcatus, Linn.), imagined the latter to be a mollusc. The treatises of the Provost Genzmer 

 of Stargard, of Professor D. J. G. Lehmann of Petersburg, of the well-known secretary 

 of the town-council of Danzig, J. Th. Klein, and of Professor Zeno of Prague, I may 

 enumerate as proofs that such an erroneous conception of the nature of Trilobites has 

 prevailed. The first termed them Conchitce ruyosi irilübi, and Lehmann,* as also Klein, 

 adopted this designation, whilst their contemporaries enumerate them by the names of 

 " Kiifer-muschel,"' and " Kakadumuschel." This determined anotlier, but more enlightened 



* In the summary of this volume, p. 56, the author ex])rcsses the same opinion as Liunseus, 

 without, however, guaranteeing its correctness. 



