300 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 18 



6. Telson with apical spines long, in P. bassi short. 



All of these characters might be used also to distinguish P. regium 

 from P. kergueleni and this is substantiated further by the excellent 

 work of Hurley 1954 who figured and described P. regium completely. 

 In discussing this problem with Dr. Hurley in person, we were able 

 to arrive at the above differentiating characteristics, except that Hur- 

 ley's figured material showed the outer plate of the maxilliped with 

 3 spines, not 5 as in P. bassi, so that this is not a valid difference. In 

 addition, his work shows that the first gnathopod of P. regium is slightly 

 but rather distinctly different from that of P. kergueleni in the shape 

 of the sixth article, which is a bit longer and slightly more slender in 

 P. kergueleni. In the examination of P. homilis n. sp., I have observed 

 that the configuration of this appendage scarcely varies in subadults so 

 that this slight difference in the two species from the southern Hemi- 

 sphere may prove to be valid. 



Although the two species P. regium and P. kergueleni are very 

 similar and at first glance of the published figures appear identical, 

 differences as stated above have been noted and should be used to dis- 

 tinguish these species until reexamination of true P. kergueleni can be 

 accomplished. The microscopic structure of the epimera of the third 

 pleonal segment is still unknown in P. kergueleni and might be useful 

 in distinguishing the species. 



The following table illustrates the differences between three species : 



bassi regium kergueleni 

 Gnathopod article 6 longer than broad O X X 



Uropod 1, rami equal X X O 



Peraeopods 1-2 with stout spine on article 2 X X O 



Phoxocephalus kergueleni (Stebbing) 



Phoxus kergueleni Stebbing 1888: 816-819, pi. 55. 

 Phoxocephalus kergueleni, Stebbing 1906: 135. 



not Phoxocephalus kergueleni, Chilton 1909: 618-619 (— >P. regium, 

 fide Hurley 1954). 



Diagnosis. — Eyes well developed and bearing lenses; gnathopod 2, 

 article 6 longer than broad; peraeopod 3, article 2 broad; epimera of 

 pleon segment 3 convex and apparently smooth behind ; outer ramus 

 of uropod 1 shorter than inner; posterior lobe of article 2 of peraeopod 

 5 expanding distally. 



Distribution. — Off Cumberland Bay, Kerguelen, 120 fms. 



