192 " THETIS " SCIENTIFIC RESULTS. 



median pair appearing to arise from the upper surface rather than 

 the sides ; terminal spine 0-4 mm. long, exceeding the distal pair 

 by 0-2 mm. ; inner angles of the front spinose, one on each side 

 of the base of the rostrum ; outer angles obtuse. 



Lateral margins of the carapace armed with six spines, the first 

 larger than those following, its apex reaching to the external 

 angle of the front ; there are two spinules near its base, one on 

 the upper surface of the carapace and the other on the margin ; 

 a third spinule is situated on the lower surface below the lateral 

 margin. The gastric spines are absent. 



Eye peduncle about 0*9 mm. long and 0*7 mm. in diameter. 



Ischium joint of the third maxillipedes longer by O'l mm. than 

 the merus ; the outer border is acute and slightly setose; the 

 distal extremity much produced and has a small obtuse spine at 

 its summit ; the inner border is also acute, bears numerous setae, 

 and terminates in a spine. The longitudinal ridge on the anterior 

 surface is armed with sixteen denticles, and there are about six 

 in the same line on the preceding joint. 



The inner border of the merus bears three spines, one at the 

 proximal third, one in the middle, and the other at the distal 

 extremity ; the outer border has two setiferous scales, one median 

 and the other distal. 



This form, should it prove to be new, adds a fifth species to the 

 group, in which the character and spinulation of the rostrum 

 agrees more or less with that of Galathea australiensis, Stimpson ; 

 the other three are G. corallicola, Haswell, G. aculeata, Haswell, 

 and G. magnifica, Haswell. According to Miers,* G. corallicola, 

 from Port Molle, " scarcely differs from G. aiistraliensis except in 

 the absence of the gastric spinules." In the type and also in the 

 rest of the specimens — about seven or eight — from Port Molle 

 the gastric spinules are present. In the original brief diagnosis 

 they are described as being absent. 



G. aculeata, Henderson,! appears to be a distinct species 

 and not G. aculeata, Haswell ; the latter has the gastric spinules 

 present, whereas in Henderson's example the "gastric spinules are 

 absent." The brief descriptions given of the above-mentioned 

 species are insufficient for correct determination, and during 

 the comparative examination of the "Thetis" material numerous 

 notes were taken with a view to rendering their identification 

 less difficult in the future. These have been used in drawing up 

 a brief account of each species. The third maxillipedes probably 

 afford the least variable specific characters, and they have been 

 described at some length. In measuring the ischium and merus 



• Miers— Zool. Coll. "Alert," 1884, p. 278. 



t Henderson — (Jhall. Rep., Zool., xxvii., 1888, p. 120. 



