(e383) 
XIV.—On the Histology of the Pedicellurie and the Muscles of Echinus 
sphera (Forbes). By Patrick GeEppzs, F.R.S.E., Lecturer on Zoology 
in the School of Medicine, Edinburgh, and Frank E. Brepparp, B.A., 
Assistant Demonstrator of Zoology, Oxford. (Plates XIX., XX., and 
XXI.) 
(Read 17th January 1881.) 
The structures known as pedicellariz were first described by O. F. MULLER.* 
He regarded them as parasitic organisms, and described under the generic 
name of Pedicellaria three species—Pedicellaria tridens, P. triphylla, and 
P. globifera. LAMARCK, in the first edition of his “ Animaux sans Vertébres,” 
published in 1801, and also in the second edition,t following MULLER, classified 
the genus Pedicellaria with the Corynide and Hydride among the naked polyps. 
Cuvier also, in the first edition of the ‘“ Regne Animal,” took the same view of 
the nature of pedicellarie. It was not until 1825 that the real nature of these 
organs was recognised. DELLE Cu1AJE,{ in his work on invertebrate animals, 
asserted that pedicellariz formed an integral portion of the Echinus, and were 
simply appendages of the test. The following quotation from his work shows 
that he thoroughly understood the true nature of these structures. He says 
(vol. ii. p. 8324) :—“ Fanno elleno parte integrale degli echini e servon loro per 
attacarsi a corpi adiacenti ed anche a ritenere gli animaletti da cibarsi.” 
The “ Monographie de lEchinus” § is the next contribution to the literature 
of this subject, and is one of the important. VALENTIN, in this work, figured and 
described the pedicellariz of Hchinus lividus, establishing at the same time the 
fact that the different forms of pedicellarie are different species, and not merely 
stages of development. Besides describing the calcareous portions, he gave 
some account of the histology of the soft parts. The nomenclature which he 
introduced is the one now generally adopted. The three varieties of pedicel- 
laria he named respectively Pédicellaires ophiocéphales, P. tridactyles, P. gem- 
miformes, and a fourth variety, which he considered to be an immature form of 
the Pédicellaires ophiocephalés, but which was subsequently proved by PERRIER 
to be an adult variety, P. tifoliés. In the following table the correspondence 
between these names and those originally applied by O. F. Mitier is given :— 
* Zoologia Danica, 1788, p. 16. 
+ Lamarck, “ Histoire naturelle des animaux sans verttbres,” 2d edition, 1815, vol. ii. p. 75. 
+ Memoria sulla storia e notomia degli animali senza vertebre del regno di Napoli, Naples, 1823-29, 
vol, li. p. 324, 
§ Vatentin, “ Anatomie du genre Echinus,” p. 46, et seq. 
VOL, XXX. PART I. 3.N 
