74 MR. H. CHARLTON BASTIAN’S MONOGRAPH 
certain minute microscopie Nematoids found in fresh or salt water, and amongst Con. 
fervæ, by other naturalists, the principal of whom are Bory ', Steinbuch *, Dugès’, Ehren. 
berg and Hemprich‘, Nordmann’, Dujardin, Oken”, Quatrefages?, Grube and Leuckart’, 
Diesing ^, Max Schultze", Leidy ^, Kühn ?, Carter", and Eberth 5. The labours, in this 
direction, of these scientific obseryers have resulted in the discovery of about eighty species 
of free Nematodes found in various parts of the world. It is, however, to the researches 
of Dujardin, Eberth, Carter, and Diesing that we have been principally indebted for ouw 
knowledge of this group. Dujardin was the first who seemed to entertain comprehensive 
notions as to the extent and probable diffusion of these animals, and, besides the dis. 
covery of several new species, added more precise descriptions of them than the extremely 
scant details concerning the anatomy of the earlier forms furnished by Otto Müller, 
Ehrenberg, Hemprich “, and others. Carter, besides the discovery of ten new species, 
has contributed many interesting anatomical details; and Eberth, in his recent valuable 
memoir ", has added much to our knowledge of their anatomy, in addition to the descrip. 
tions and beautiful figures which he has given of twenty-three new species ; though he, like 
his predecessors, has tended to create great confusion in the nomenclature, by describing 
under the same generie name species differing notably in the anatomical arrangement 
of important parts, as I shall hereafter endeavour to explain. It is by his writings, 
rather than by special anatomical examinations of his own, that Diesing's name is ass 
ciated with this group, since he has not only treated of them in his ‘Systema,’ but 
also has lately made the classification of the Nematodes, both free and parasitic, the 
subject of a special communication 55. 
The writings of Carter afforded the stimulus which induced me to inquire into this 
Subject; for, like himself, having been interested in the anatomy of the Dracunculus”, 
my attention was arrested by his interesting paper on the “ Microscopic Filaridæ in the 
Island 'of Bombay” *, and my search for similar free Nematoids in this country has bee 
, Encycl. Méth. 1824, p. 777, tab. iv. f. 20-23. 2 Naturforsch. xxviii. St. 233, tab. v. 
* Ann. des Sc. naturelles, 1826, tom. ix. p. 225. * Symb. Phys., seu Icones et Descrip. Animal. evert. 1825. 
* Lamarck's Hist. Nat. des Ann. sans vert. 1840, tom. iii. p. 665. ; 
, Hist, Nat. des Helminthes (Suites à Buffon), 1845, p. 230. 7 Lehrb. d. Naturg. Zool. 1. Abtheil. p.192 
° Ann. des Sciences Nat. 1846, p. 131. ? Wiegmann, Archiv, 1849, Band i. pp. 15% 358. 
" Systema Helminthum. Vindobonæ, 1851, vol. ii. p. 122, " Icones Zootomicæ, Carus, tab. viii. figs. t 
© Journ. of Acad. of Nat. Sc. of Philadelphia, vol. iii. (1856) pp. 135-152 (2 plates). 3 
P? Zeitsch. für wissen. Zool. 1857, t. ix. p. 189. ; # Ann. of Nat. Hist. 1859, vol. iv. pp. 28 and 98, pi! , 
a Untersuch. über Nematoden, mit neun Kupfertafeln. Leipzig, 1863. ansto- 
xt A meeps to recognize the species of these authors seems quite hopeless, since, oftentimes, no other : 
— details are given, save the mere length and breadth, and for figure, if any, only a mere outline form —oecasionalf 
a simple white Space on a black ground. 
S My species were already found, drawings made, and a rough draft of this paper written before 1 2 
coincidence, however, 
ervers, 
eas : 
,, Sitzungsberichte der Wiener Akademie, 1861, Bd. xii. no. 28, p. 612. 
' Transactions of the Linnean Society, vol. xxiv, part 2, p. 101. 2 Loc. cit. 
„e 
