ACANTHONOTOZOMATIDAE 123 



Apart from the size of the eye, the antero-lateral margin of the head forms a good 

 distinguishing character. 



The colour is given as "white and semitransparent with a pair of patches of brown 

 chromatophores at base of foremost pair of dorsal spines; other scattered brown 

 chromatophores at base of other dorsal spines and on basal segments of legs and 

 antennae; eyes pink". 



Genus Anchiphimedia, Brnrd. 

 Barnard, 1930, p. 357. 



Anchiphimedia dorsalis, Brnrd. 

 Barnard, 1930, p. 357, figs. 29, 30. 

 Occurrence: St. 187. Palmer Archipelago. 1 $ 12-5 mm. 



Remarks. The tooth on the postero-lateral margin of pleon segment 3 and that on 

 the postero-inferior angle of the same segment are both longer and more upturned, and 

 the excision between the former and the gibbous dorsal apex of the segment is less 

 angular. 



The dorsal processes are markedly thick or even somewhat clavate, not like the 

 evenly tapering processes of other species. In other respects the specimen is quite 

 typical. 



Distribution. McMurdo Sound, 547 m. 



Genus Labriphimedia, Brnrd. 

 Barnard, 193 1, p. 427. 



Epistome short and broad. Upper lip transverse, much broader than long, not 

 incised. Mandible tapering to a smooth, symmetrical, spoon-shaped apex, secondary 

 cutting-plate present or absent, molar rudimentary, no spine-row. Lower lip without 

 inner lobes, outer lobes not apically incised. Maxilla 1 with stout 2-jointed palp which 

 extends beyond apex of outer plate. Maxilliped with inner plate moderately broad, 

 outer plate broad , palp rather slender, 2nd joint neither expanded nor apically produced . 



Remarks. In the Terra Nova Report (p. 358) I assigned Iphimedia pulchridentata, 

 Stebb., to the genus Echiniphimedia in spite of certain details in the mouth-parts. The 

 discovery of the species described below, which agrees with pulchridentata in the 

 general shape of the mandible and maxilliped, as well as in the short broad labrum, 

 clearly indicates that both should be placed in a new genus. 



Among several types of mandible found in the members of this family the peculiar 

 scoop-like apices of the present form are quite distinctive and indicate a diet quite 

 different from that of Gnathiphimedia , for example. 



The transverse upper lip connects this genus with Maxilliphimedia, but it is well 

 separated by the other mouth-parts, though the stout maxillary palp shows a tendency 

 to evolve in the direction of the latter genus. 



The species described below is designated as the genotype. 



16-2 



