Chilton. — -Some Australian and New Zealand Gammaridae. 367 



seem always to reach well beyond those of the preceding pairs, and they 

 are considerably elongated in some of the New Zealand specimens ; in 

 one of the specimens from the Chatham Islands they are much shorter on 

 both sides, hardly reaching beyond the second and third, but I think 

 this condition is abnormal, and due to the regeneration of appendages 

 that had previously been lost. Walker has pointed out that the fourth 

 and fifth peraeopoda are more massive and spinous in the Ceylon than 

 in the Mediterranean specimens, and has also drawn attention to the fact 

 that the species forms a connecting-link between the genera Maera and 

 Elasmopus, mentioning among the characters that resemble the latter 

 genus the comparatively short rami of the third uropods. In the New 

 Zealand specimens, however, they are quite long enough to justify the 

 inclusioia of the species in Maera, and the species appears to differ also 

 from Elasmopus in having the second gnathopods of approximately the 

 same size in both sexes, and in having the setae on the inner surface of 

 the carpus of the first gnathopod arranged on a different pattern. 



Maera hirondellei Chevreux differs from the more typical forms in 

 having the accessory appendage shorter, and in the oblique palm of the 

 second gnathopod of the male ; but these differences are perhaps only of 

 varietal importance. The general resemblance in other characters is very 

 close. 



Miers mentions (1884, p. 569) that in the British Museum there is a 

 specimen from the Korean Seas which cannot, he thinks, be distinguished 

 from M. truncatipes (Spinola) — i.e., from M. inaequipes (A. Costa). M. diversi- 

 tnana Miers appears also to be closely allied to the present species and 

 to M. viridis Haswell, but apparently differs in having the segments of the 

 pleon dorsally toothed, and in having the right and left second gnathopods 

 unequal in size. Mobile in M. inaequipes they are, according to Stebbing, as 

 a rule, " quite alike in size and sculpture." The name of the species, how- 

 ever, indicates that this is not always so, and probably in this as in other 

 species with large gnathopods the appendage on one side may differ fi-om 

 that on the other in some individuals, while in others they are alike. 



Maera mastersii (Haswell). 



Megamoera mastersii Haswell, 1879, p. 265, pi. 11, fig. 1. Moera 

 quadrimana G. M. Thomson (part), 1882, jd. 235, pi. 17, fig. 46 

 (not M. quadrimana Dana). Megamoera thomsoni Miers, 1884, 

 p. 318, pi. 34, fig. B. Maera mastersii Stel)bing, 1906, p. 439 ; 

 1910a, p. 642 ; 1910b, p. 457 : Chilton, 1911, p. 564. 



Specific Diagnosis. 



Body smooth, none of the segments lieing dorsally produced into teeth. 

 First side plate produced anteriorly into a rounded lobe. Third pleon 

 segment with lower portion of posterior margin serrate, inferior margin 

 with 2 setae but not serrate. Eyes narrowly reniform. First antenna 

 with accessory flagellum short, usually of not more than 4 joints, primary 

 flagellum as long as peduncle, fairly stout, setose. First gnathopod with 

 carpus as long as propod, its inner surface with tufts and comb-like rows 

 of setae, propod slightly narrower than carpus, palm smooth, somewhat 

 oblique, not defined. Second gnathopod considerably larger, merus pro- 

 duced into sharp tooth, carpus about half the length of projiod, which is 

 oblong with margins parallel and provided with many tufts or transverse 



