370 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



Fig\ 6. Right second maxilla, showing* long curved 



spines. 

 Fig. 7. Maxillipeds, viewed from under side, showing 



that they are joined to form a lower lip. 

 Fig. 8. First gnathopod from left side, showing coxal 



plate (e.p.) attached to coxopodite. 

 Fig. 9. Second gnathopod (left), showing coxal plate 



and branchia (c.p. and br.). 

 Fig. 10. First perreopod, showing hooked dactylopodite, 



coxal plate and branchia. 

 Fig. 11. Telson, showing two apical spines, and one 



lateral one on each of the two rami. 

 Fig. 12. First pleopod (left) showing long plumose setse 



on many- jointed similar endopodite and 



exopodite, and single spine on protopodite. 

 Fig. 13. Last epimeral plate (left) of metasome, showing 



somewhat pointed infero-posterior corner. 

 Fig. 14. Last uropod (left), showing plumose setre and 



exopodite, and single spine on protopodite. 

 Fig. 15. The eye, showing the somewhat quadrangular 



pigmented ommatidia. These are variable 



in number. 



Plate II. 



of male Gammarus jmlex, seen extended in 

 optical section from the left side, and enlarged 

 twenty times. The diagram is built up from a 

 number (560) of transverse serial sections, 

 stained with Mann's methyl blue eosin. The 

 heart and the aortee, which are cut short, are 

 coloured pink. The pericardium and the 

 other vessels are omitted. The nervous 

 system is dense black and the alimentary canal 



