Cnistacca. 245 



Three specimens were taken off' the Auckland Islands in ten 

 fathoms of water. 



No conspicuous difference is exhibited by any of these specimens 

 beyond the presence or absence of the two dark spots on the first 

 thoracic segment. This may be. and probably is, a very variable 

 feature. 



CyMODOCEA AUSTRALIS. 

 (PI. XXXlir., fig. .3, and PI. XXXIV., fig. .3.) 



The body is twice as long as broad and covered, though not very 

 closely, with short and fine setae. 



Cephalon is rounded in front, longer than any of the thoracic 

 segments. Eyes moderately large, and that region of the cephalon is 

 produced slightly backwards on to the first thoracic segment. 



The first segment of the thorax is the length of the two following, 

 and they all gradually shorten slightly and progressively to the 

 posterior. The pleon is marked in rather a complex manner. The 

 first segment bears a thumb-like elevation directed forwards and 

 outwards which lies between the mid-dorsal line and the lateral 

 margin. The two following segments are incompletely separated 

 and together form a very broad V-shaped structure on the pleon ; the 

 extremity of the arms of the V just extend to the margin of the body 

 and are bi-lobed, the posterior lobe being the shorter. The base 

 of the V is a free backwardly-directed spine. The last pleon 

 segment has the postero-lateral margins curved boldly towards 

 the middle line, the extremity is broadly notched, and the notch 

 is almost completely filled with a rounded lobe. A short way 

 in front of this in the middle line is a rounded tubercle. The 

 uropods are very conspicuous and project beyond the extremity of 

 the body. The inner branch is much the largest and lies parallel 

 to the postero-lateral margin of the pleon. It forms an oblong 

 structure, roughly rectangular. The outer branch forms a truncated 

 cone. 



First antenna. Peduncle two-jointed, the first being long and 

 stout, widest distally. Second joint small, partly sunk in the 

 extremity of the first, expanded laterally into a somewhat triangular 

 form. Flagellum ten-jointed, first joint longer than the two 

 succeeding, fourth joint conspicuously larger than the second or third 

 and the remainder becoming reduced in size. 



Second antenna. Peduncle three-jointed, the third as long as the 

 other two. Flagellum nine-jointed. 



