Dr. Ti Scott on British Copepoda. 466 



relationship somewhere between Diosaccus, Boeck, and 

 AmphiascuSj G. 0; Sars, but it appears to be more nearly 

 allied to the first; it differs, however, generically I think 

 from both. The outer ramus of the posterior antennas is 

 two-jointed. The mandibles have the biting-edge armed with 

 distinct though somewhat irregular teeth. The maxillae 

 differ from the same appendages in Diosaccus in being 

 compact in structure (in this respect they more nearly resemble 

 those of Amphiascus), and the inner branch of the fourth 

 pair of thoracic legs is composed of only two joints. 

 The species appears to be rare. 



EXPLANATION OF PLATE XL 



D ' Arcythompsonia fairliensis, T. Scott. 



Fig. 1. Female, seen from the side. 



Fig. 2. Male, seen from the side. 



Fig. 3. M mdible and mandible-palp. 



Fig. 4. Foot of second pair, male. 



Fig. 5. Last abdominal segment and f ureal j oints, female, dorsal view. 



Fig. 6. Last abdominal segment and f ureal joints, male, dorsal view. 



Pteropsyllus consimilis, T. Scott. 



Fig. 7. Foot of first pair. 



Fig. 8. Foot of fifth pair, female. 



Harrietella simidans, T. Scott. 



Fig. 9. Female, dorsal view. 



Fig. 10. Foot of fourth pair, female. 



