SEA-FISHERIES LABORATORY. 423 



the second maxillipede. It passes directly backward and 

 lies upon the fused epimera of the first and second 

 thoracic somites. Its long axis is at right angles to that 

 of the first gill. Length 25 mm. 



Third gill. Podobranch of the third thoracic somite 

 (g. 3). Arises from the elongated coxopodite of the third 

 maxillipede. It is extremely short and is wedged in 

 between the first and fifth gills, at the base of the latter. 

 Length 7 mm. 



Fourth gill. Anterior arthrobranch of the third 

 thoracic somite (g. 4). Arises, together with the fifth 

 gill, from the arthrodial membrane of this somite. It 

 lies on the thoracic epimera, immediately behind the 

 second gill. Length 26 mm. 



Fifth gill. Posterior arthrobranch of the third 

 thoracic somite (g. 5). Arises from the same place as the 

 fourth gill, and lies immediately behind the latter. Its 

 base is notched in order to receive the third gill. Length 

 25 mm. 



Sixth gill. Anterior arthrobranch of the fourth 

 thoracic somite (g. 6). Arises together with the seventh 

 gill from the arthrodial membrane between the chela and 

 the fourth thoracic somite. It lies behind the fifth gill. 

 Total length 37 mm. 



Seventh gill. Posterior arthrobranch of the fourth 

 thoracic somite (g. 7). Arises from the same place as the 

 sixth gill and lies immediately behind it. Total length 

 37 mm. 



Eighth gill. Pleurobranch of the fifth thoracic 

 somite (g. 8). Arises from the epimeron of this somite. 

 Total length 28 mm. 



Ninth gill. Pleurobranch of the sixth thoracic 

 somite (g.9). Arises from the epimeron of this somite, 

 upon which it lies, immediately behind the eighth gill. 



