GAMMARIDEAN AMPHIPODA 29 



JMaterial. — Two specimens from the type-locality. 



Relationship. — The yoiithfulness of the specimens probably ac- 

 counts for the poor spination and setation on various appendages but 

 the subgeneric characters are not the result of juvenility. 



Ischyroceridae 



Bonnierella Chevreux 



Bonnierella palenquia, new species 



Figure 13 



Diagnosis. — Similar to Bonnierella linearis J. L. Barnard (1964b) 

 in characters of head, pleon, telson, and generally in mouthparts but 

 mandibular molar with 1 short seta, article 4 of maxillipedal palp 

 shorter, and upper lip with slightly deeper excavation than in B. 

 linearis; epistome with anterior cusp as in B. I. califomica J. L. 

 Barnard (1966a); gnathopods and pereopods generally like B. I. 

 linearis but second articles of pereopods 3-5 slightly stouter ; uropods 

 distinct from those of B. I. linearis^ as follows: distal end of peduncle 

 of uropod 1 with three cusps, medial longest and nearly half as long 

 as outer ramus and basally nearly twice as thick, base of inner ramus 

 attached submarginally on shelf formed by medial cusp, ventrome- 

 dial cusp slightly more than half as long as medial, lateral cusp about 

 half as long as ventromedial; uropod 2 with sharp medioventral cusp 

 about one third as long as outer ramus, medial cusp slightly more than 

 half as long as other, lateral cusp obsolescent ; uropod 3 similar to that 

 of B. I. califomica. 



HoLOTYPE.— AHF No. 6130, female, 3.2 mm. 



Type-locality.— Station 7358, 27°35'45" N, 115°08'30'' W, 1095- 

 1205 m, Apr. 21, 1961. 



Material. — Two specimens from the type-locality. 



Relationship. — The occurrence of more than one large distal cusp 

 on the peduncles of uropods 1 and 2 distinguishes this species from all 

 others in the genus. J. L. Barnard (1964b) has a key to those species 

 but leaders 2 and 3 of couplet 1 are reversed and the key is recomposed 

 in sequel. 



Key to the Species of Bonnierella 



1. Posterior margin of article G on male gnathopod 2 shorter than palm ... 2 

 Posterior margin of article 6 on male gnathopod 2 longer than palm .... 4 



2. Uropod 1 with large distomedial peduncular cusp half as long as outer ramus, 



a shorter ventromedial cusp and a shorter lateral cusp, uropod 2 with two 

 short distal peduncular cusps, one medial, one ventromedial. 



B. palenquia, new species 



