334 



four segments. The mandibles have a palp in both sexes. The outer lobes 

 of maxillae I bear five terminal spinules. The inner lobes of maxillipeds 

 are well developed, with two apical setae. 



The coxal plates are free, pereopods I have a weakly developed 

 chela; the 5th segment is triangular, broadened distally, and its posterior 

 distal corner produced into a triangular lobe. Pereopods II have a chela 

 formed by the 6th segment and process of the 5th segment. In pere- 

 opods III and IV the 5th segment is linear. Pereopods V (or V and VI) 

 are distinctly longer than the other pairs. Pereopods VII (or VI and VII) 

 are approximately equal in length and not longer than pairs III and IV. 



Type species: Hyperiella antarctica Bovallius, 1887. 



Hyperiella is closer to Hyperia because of the large head, thickset 

 body, and structure of pereopods I and II, but its long pereopods V and 

 narrow elongated uropods bring it closer to Parathemisto. 



This exclusively Antarctic genus includes three close species that 

 are not well distinguished from each other. 



KEY TO SPECIES OF GENUS HYPERIELLA 



1. Pereopods VI a little longer than V. Basipodite of uropods III twice 

 longer than telson 3. H. macronyx (Walker). 



— Pereopods V notably longer than VI. Basipodite of uropods III more 

 than twice longer than telson 2. 



2. Lower posterior angle of epimerons I-III stretched and acuminate. 

 Distal anterior angle of 2nd, 3rd, and 4th segment of pereopods V-VII 

 stretched into acute denticles. Telson same length as urosomite III . . 

 2. H. dilatata Stebb. 



— Lower posterior angle of epimerons II-III only slightly acuminate, 

 distal anterior angle of 2nd, 3rd, and 4th segments of 

 pereopods V-VII straight, not stretched. Telson shorter than 

 urosomite III \. H. antarctica Bov. 



1. Hyperiella antarctica Bovallius, 1887 (Fig. 137) 



Bovallius, 1887a: 20; 1887c: 566; 1889: 242; Stebbing, 1888: 1407; 

 Barnard, 1932: 275; Hurley, 1969: 32. 



Length of sexually mature specimens 6-8 mm. 



The description is based on a male. The body is thickset and the 

 integument thick and hard. The head is distinctly higher than the pereon, 

 broad, and longer than the first three somites together. 



Antennae I in males extend only to somite V of the pereon; the 

 flagellum has ten segments, its oval-conical 1st segment is twice longer 

 than the whole peduncle, and the other segments are narrow and short. 

 Antennae II are somewhat longer than antennae I but do not extend to 



