TANAIDACEA AND ISOPODA— TATTERSALL. 215 



Remarks. —It is not possible to name this larva, but it seems to belong to 

 this sub-family, and indeed probably to the genus Ceratothoa or its relative, Meinertia. 

 It is in the second stage of larval development, and the dactylus of the three anterior 

 pairs of limbs is armed with five teeth. .Four species of the genus Meinertia are 

 known from New Zealand waters, and it is probably to one of these that this larva 

 should be referred. 



Family SPHAEEOMIDAE. 

 Sub-family LIMNORIINAE. 



Genus LIMNORIA, Leach. 

 22. Limnoria antarctica, Pfeffer. 



L. antarctica, Pfeffer, 1887, p. 96, pi. II, figs. 12, 13, pi. V, figs. 2-22 ; Stebbing, 1904, p. 714 ; 

 Caiman, 1910, p. 185; Richardson, 1913, p. 8; Chilton, 1914, p. 382, pi. XVII, fig. 8; 

 Chilton, 1914, p. 448. 



Occurrence. — Cumberland Bay, S. Georgia, December, 1913, collected by P. 

 Stammwitz, one. 



Sub-family PLAKARTHRIINAE. 



Genus PLAKARTHRIUM, Chilton. 

 23. Plakartlirium tyjncwm, Chilton. 



P. tijpicum, Chilton, 1883, p. 74, pi. I, figs. 5-57i; ; Thomson and Chilton, 1886, p. 159 ; 

 Hutton, 1904, p. 263 ; Hansen, 1905 (1), p. 115. 



Occurrence. — Station 135, Spirits Bay, near North Cape, New Zealand, plankton, 

 one male. 



Remarks. — The specimen measures 4 mm. in length, and agrees very closely with 

 Chilton's description. As Hansen notes, the species is very closely allied to P. punc- 

 tatissimum, Pfeffer; but I have been able to examine a specimen of the latter species 

 in the collections at the British Museum identified by Prof. Chilton from collections 

 made by Dr. W. S. Bruce at the South Orkneys, and I am convinced that the two 

 species, though very closely related, are distinct, and readily separable by one 

 important character. This is the form of the thoracic legs, and a comparison of the 

 original descriptions of both species brings out the fact that both Pfeffer and Chilton 

 have accurately described the thoracic legs in their respective species. Pfeffer states 

 that in P. j'^unctatissimum " Die Beine sind nach zwei ganz verschiedenen Typen 

 gebildet. Das 1 , 2 und 7 Paar sind schlank, haben lange Femora und 2 Endklauen ; 

 die iibrigen sind kiirzere und feste Klammerfiisse mit ganz kurzen Femur und ein- 

 facher, grosser Endklaue." Chilton's original description of P. typicum reads: "First 

 two pairs of legs slender, three following pairs short and stout, last two pairs slender, 



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