10 HISTORY OF THE SUBJECT. 



P. S. Pallas, 1 in the year 1766, described a Nemertean of a bluish-white colour under the 

 name of Lumbricus oxyurus, which I am inclined to identify with Amphiporus lactifloreus, from a 

 careful examination both of the figures and text. He mistook the proboscis for an intestine, as 

 many subsequent authors have done, but he observed that the organ was bathed in fluid, thus 

 recognising a very important element in the anatomy of these animals. He interpreted the stylet- 

 region as the stomach, and detected three muscular bundles proceeding from the posterior end of 

 the latter, so as to fix the organ to the integuments. The intestine, again, terminated in an anus 

 at the anterior pore. The medulla or nervous trunk formed a simple white cord, he said, without 

 ganglia. While there is much that is erroneous in the foregoing description, there is also a con- 

 siderable amount of penetration and judgment evinced by the learned author, for he appears to 

 have made out the proboscidian fluid, the dilated region of the stylets, and the muscular ribands; 

 and it is clear that this observer would not have omitted to notice the mouth and lateral 

 fissures if his specimen had been a typical form of the Anopla. In the same work 3 he also 

 figures a Nemertean resembling Lineus gesserensis, but the only reference thereto occurs in the 

 explanation of the Plate, viz., " Alia Lumbrici marini species, tota atra." 



The next important contribution was from the pen of the distinguished naturalist, Q. P. 

 Miiller, 3 who in. the first part of his " Vermium," published in 1773, grouped the Nemerteans 

 under the Second Division of his worms destitute of tentacles (Serpentes), and in the third head 

 (Mutica). In his second part, published in 1774, they were included, along with Gordius, 

 Ascaris, Hirudo and others, in the first subdivision (Mutica) of his Gens Helminthica. 

 Three or four of the common species were for the first time described (some of them more than 

 once) as Fasciolce. 



In the new edition of his " Natural History of Fresh and Salt Water Worms/' 4 published in 

 1800, the same author describes a single example of the IAneidm under the name of c Der Stro- 

 mische Hod-Aat/ a species no doubt identical with Lineus gesserensis. He did not discriminate 

 structure further than by supposing the lateral slits at the anterior end to be connected with the 

 anus, and the ventral papilla (mouth) the male organ of generation. His figures are quite 

 recognisable. 



This naturalist 5 in a subsequent publication (1776) enumerates the Nemerteans under his 

 sixth Class (Vermes), and third Order — Mollusca. It is difficult to determine with precision the 

 species referred to in this work, unless in those cases in which further mention in the " Zoologica 

 Danica" confirms the diagnosis. He arranged them with the Planarise according to the number 

 of eyes, but erroneously placed Lineus gesserensis, Amphiporus pulcher, and others, under the 

 group of eyeless forms. 



The acute and painstaking Dutch naturalist, Martin Sfabber, 6 noticed a Nemertean, under 

 the name of Gordius marinus, which is evidently one of the Anopla, having in his figure (where 



1 P. S. Pallas, f Miscellanea Zoologica/ pp. 146—147, pi. 11, figs. 7 and 8. 



2 Op. cit., p. 216, pi. 11, fig. 9. 



3 O. F. Muller, 'Vermium Terrestrium et Fluviatilium.' Havnise et Lipsiae, 1773-4. 



4 l Naturgeschichte einiger Wurm-Arten des siissen u. salzigen Wassers/ Neue Ausgabe. Ko- 

 penhagen, 1800. 



5 O. F. Muller, c Zoologise Danicse Prodromus/ Havnise, 1776. 



6 ' Natuurkundige verlustigingen behelzende microscopise waarneemingen/ &c, Blad. 61, PI. 8, 

 f. 1. Haarlem, 1778. 



