Boone, Crustacea, Cruise of "Alva," 1931 219 



first three segments are nearly straight. The fourth, fifth and 

 sixth segments are subequal, each being about one-fourth shorter 

 in the median line than the third segment ; the seventh segment 

 is very short in the median line, about one-half the length of the 

 sixth segment. The epimera of the second to seventh segments, in- 

 clusive, are clearly defined, extending across the entire lateral mar- 

 gin of the related segment. On segments four to seven, inclusive, 

 each, there is an oblique sulcus running inward. The postlateral 

 margin of each epimera is rounded. There is an oblique carina 

 running inward on each epimera, identical with those in Dana's 

 figure, but less sharply defined in the present young specimens. 

 All seven pairs of legs are prehensile ; the first three pairs being 

 directed forward and the remaining four pairs posteriorly. The 

 third pair of legs have long, curved, hook-like dactyli. The seventh 

 pair have the dactyli acute and much shorter than those of the 

 third pair. 



Abdomen: The abdomen is slightly narrower than the thorax; 

 segments one, two and three are subequal, each is about as long 

 as the seventh thoracic segment ; segments four, five and six are 

 each slightly shorter than the preceding segment and definitely 

 narrower, their lateral portions being more appressed. The telson 

 is about as wide proximally as long, with the distal margin widely 

 rounded. The uropoda has a strong peduncle, both blades are 

 longer than the telson ; the inner blade is a little wider than the 

 outer and has the distal margin unequally rounded, being some- 

 what truncate on the inner side; the outer, narrower blade is 

 evenly rounded distally; both have the margins ciliated. 



References: Aegathoa macrophthalma, Dana, J. D., U. S. Ex- 

 plor. Exped., vol. XIII, Crust, pt. 1, 1852, p. 765 ; Atlas, 1855, 

 pi. 50, fig. 12a-e.— NiERSTRASZ, H. F., "Siboga"-Expeditie, 

 Livr. 114, Isopoda III, Monogr. 32C, Flabellifera II, 1931, p. 

 146, Leiden. 



Family: CORALLANIDAE 



Genus: ARGATHONA Stebbing 



Argathona confine Hale 



Plate 65 



Type : A female taken at Albany Passage and deposited in the 

 Australian Museum, Reg. No. 8205. 



