THE ANATOMY OF SCALIBEEGMA INFLATUM. 239 



Dr. Theel^ of Stockholm, and Dr. Appellof, of Bergen, for the 

 gift of several excellent specimens from the coast of Norway. 

 This work has been done in the Beyer Zoological Labora- 

 tories of the Owens College, Manchester, and in the Zoological 

 Laboratory of the University of Edinburgh. 



2. Historical Account. 



Rathke (1843, p. 182) founded the genus and species 

 Scalibregma inflatum upon specimens obtained at Molde, 

 in Norway. He described the external characters in con- 

 siderable detail, directing attention to the form of the para- 

 podia in different regions of the body, and to the brown or 

 black structures upon them. 



Three years later M. Sars (184G, p. 91) was fortunate in 

 securing a very large specimen (58'5 mm. long), which he 

 described under the name Oligobranchus rose us. He 

 has given a good account of most of the external characters 

 of the animal, but overlooked the black structures on the 

 parapodia. He considered this animal was allied to the 

 newly described genus Eumeuia, Oersted, and he also men- 

 tioned its general aflBnity with the Ariciid^ and the Areni- 

 colidas. 



Danielssen (1859, p. 69) has given the only account of the 

 internal anatomy of Scalibregma. The form of the ali- 

 mentary canal, the circulatory system, the nervous system, 

 the paired segmeutally arranged organs — interpreted by him 

 as ovaries, — and the structures he mistook for testes are 

 described in considerable detail and illustrated by clear 

 figures. 



In 1873 Verrill (1873, p. 605) described the external 

 features of a new species, S. brevicauda, which had been 

 obtained off Newhaven, Connecticut, U.S.A., and Hansen 

 (1882, p. 34) found among the material of the North Atlantic 

 Expedition specimens which he referred to new species, S. (?) 

 abyssorum and S. (?) parvum. Wiren (1887) made 

 scattered references to some points in the structure of the 

 alimentary canal, and the arrangement of the muscles and 



