436 F. W. GAMBLE. 



of papers by Dr. George Johnson, and Wm. Thompson, of 

 Dublin. The former, under the title ' Illustrations of British 

 Zoology' (11 and 12), described Planaria cornuta 

 (Eurylepta cornuta) and Planaria subauriculata 

 (Stylochoplana subauriculata) from the shores of Ber- 

 wick Bay. These accounts suffice to enable us to identify the 

 species referred to, but give little idea of their internal anatomy. 

 The relations of the known forms to one another were as yet 

 quite obscure. Thompson recorded forms from various Irish 

 localities. Forbes and Goodsir found Polyclads in the 

 Orkneys and Shetlands in 1839 (13), and in his later dredging 

 reports Forbes frequently enters '^^ Planaria sp. ?" accom- 

 panied by a lament that so little is yet known of these forms. 



If we turn to work done on the Continent during this 

 period (1830 — 1850) we find that v. Baer and Duges had inde- 

 pendently discovered the internal anatomy and especially the 

 generative organs of the fresh- water Planariae, and had proposed 

 a rough scheme of classification. The corresponding discovery 

 of the anatomy of Polyclads was made by v. Mertens.^ 

 Ehrenberg (10) had found many new forms, some of which 

 constituted his subdivision " Rhabdocoela." Oersted's most 

 important paper (16) appeared in 1844,^ containing a system 

 which included all known species, and from which later 

 attempts originate. Our knowledge of the histology and 

 anatomy of the Rhabdocoeles (the small size of which usually 

 prevented an adequate investigation being made, on account 

 of the necessity for high magnifying powers) was immensely 

 increased by Max Schnitzels ' Beitrage zur Naturgeschichte 

 d. Turbellarien,' 1851. The accuracy of the descriptions and 

 beauty of the copper plates are well known. 



The following year (1852) Dalyell published the ' Powers 

 of the Creator,' the second volume of which contains references 

 to a considerable number of Turbellaria. Among these, 



* '• Untersuchungea ii. d. Bau verschiedener in d. See Icbender Planarien," 

 'Mem. de I'Acad. Imp. d. Sciences d. St. Petersbourg,' s6r. 6">e^ t. ii, 1833. 



^ Reprinted witli figures and additions from ' Kroyers Naturliist. Tids- 

 skrift," 1843. 



