22 HISTORY OP THE SUBJECT. 



cavity common to the generative, digestive, and respiratory functions, and a small dorsal vessel 

 analogous to the intestinal canal of Nemertes. 



A very interesting brochure on the Nemerteans 1 was contributed by Prof. Kolliker in 1845, 

 a paper, I may remark, which has received too little attention from some continental writers. 

 After indicating the ordinary characters of the group, the author gives a general account of their 

 anatomy, correctly describing the mouth, alimentary canal and anus, the situations of the ganglia 

 and the branches of the lateral nerves. Pie also notes the occurrence of lenses in the eyes of 

 certain species. He is in error, however, when he states that he found two hearts with coloured 

 blood in the head of Nemertes roseus ; and that the proboscis is attached to the wall of the 

 body posteriorly. He observed the stylet-apparatus in several species. His classification of the 

 Nemerteans was founded, somewhat curiously, upon the presence or absence of a sheath to the 

 proboscis, thus : — (1) With the proboscis floating freely in the body-cavity; body ciliated, and 

 smoothly rounded. (2) With a smooth body, and the proboscis confined in a sheath. The 

 latter group he again subdivided into (a) those with a flattened head and lateral furrows, and 

 (b) those having neither a flattened head nor lateral furrows. He describes ten species, most of 

 which are stated to be new. One of these is the strange Nemertes carcinopldla, which he found 

 in an apparently parasitic condition amongst the ova of the common shore-crab. 



Dr. Johnston, in his 'Index to the British Annelides ' 3 (1846), described a few additional 

 Nemerteans ; but this paper does not require further mention at present, except to observe that 

 he arranged his species under five genera, viz., Borlasia, Zineus, Serpent aria, Meckelia, and 

 Prostoma, which were comprehended by the Sub-family Linince of the Family Planariada, Tribe 

 Nemertinea and Order Apoda. 



In the same year (1846) M. de Quatrefages published his observations on the Nemerteans, 3 

 but as a more complete edition of his acute and comprehensive labours (especially as regards figures) 

 subsequently appeared, I shall in the meantime reserve further criticism. A notice of this paper, 

 with an appendix of his classification, was given in Proriep's ( Neue Notizen/ 4 Before the 

 appearance of the foregoing, he had also made some remarks on the proboscidian fluid and 

 circulation of the Nemerteans in his " Note sur le sang des Annelides " in the previous volume (V) 

 of the ' Annales.' 



This author observes 5 that he had found in the rocks of Solenhofen certain imprints 

 which he considered difficult to attribute to other than Nemerteans. The impressions indicate 

 cylindrical coiled animals, resembling these worms after immersion in alcohol. In the chips of 

 stone from Strasbourg he thought the forms referable to the Genus Borlasia, and especially 

 resembling Zineus marinus. 



In 1847 the celebrated J. Miiller 6 described and figured Pylidium gyrans, as a larva from 

 Heligoland ; but he did not then find out its connection with the Nemerteans, and indeed was 

 in doubt as to its actual relations. 



1 e Verhandlungen der Schweizerischen Naturforschenden geseilschaft bei ihrer Versammlung zu 

 Chur, 1844/ pp., 89—93. Chur, 1845. 



2 l Ann. Nat. Hist./ vol. xvi (Supplement), pp. 433—462, pi. xv. 



3 " Etudes sur les types inferieurs de rembranchement des anneles. Memoire sur la Famille des 

 Nemertiens" (Nemertea). e Ann. des sc. nat./ 3eme ser., Zool., torn, vi, pp. 173 — 303, pis. viii — xiv. 



4 Froriep's ' Neue Notizen/ bd. xxxix, 1846, p. 276. From the < Institut/ No. 660, 26 Aug., 1846. 



5 " Soc. Philom. Extr. Proces verb. 1846/' < I/Institut/ xiv, 1846, No. 664, p. 154. 



6 < Archiv fur Anat./ 1847, p. 159, taf. vii, f. 1—4. 



