352 LIVERPOOL MARINE BIOLOGY COMMITTEE REPORT. 



pared with var. capeiisis in Pallas's work, and taking into 

 account the indistinctly double series of teeth shewn in figs. 

 5, 8 and 9 of var. belgica, I think that probably the former 

 view is the most likely to be the correct one. In that case 

 P. auricoma of Miiller disappears, and becomes P. belgica 

 of Pallas. 



Dalyell, then, is right in considering them as one form, 

 and Malmgren is right in figuring as P. belgica a form 

 with a comb in all respects identical with that described by 

 Miiller as peculiar to P. auricoma. Other writers have pro- 

 bably not compared the original authorities, and so have 

 simply taken for granted the existence of two distinct species. 

 I have reproduced in Plate VIII (figs. 5-7) the original 

 figures of Miiller and Pallas in order that they might be 

 compared with that of Malmgren (fig. 8). 



Explanation of the Plates. 



Plate VII. 



Malmgrenia castariea, Mcintosh. 



Fig. 1. Transverse section of the body, magnified 50 dia- 

 meters. 



Fig. 2. Transverse section of the sub-intestinal pseud- 

 haemal vessel, magnified 300 diameters. 



Fig. 3. Transverse section of the elytron-bearing protuber- 

 ance, magnified 300 diameters. 



Fig. 4. The bases of the acicula, shewing the mode of 

 attachment of the muscles, magnified 300 diame- 

 ters. 



Fig. 5. Transverse section of the alimentary canal and its 

 caeca, magnified 300 diameters. 



Fig. 6. The dorsal surface of four segments from the 

 middle of the body, magnified 50 diameters. 



