FROM CHEISTMAS ISLAND. 287 



CORYCELLA Sp., S • (PL XI. figS, 8, 9.) 



There were present numerous specimens of males of CoryceUa 

 belonging to at least two species judging by size alone, as in other 

 characters they seemed to be in agreement. These doubtless 

 represent the males of C. gibbula, C. concinna, and C. carinata, 

 but I have not been able to i-efer them to their respective females. 

 In size the brger measured "85 mm. and the smaller •78-*8 mm. 

 Dahl's (6) recognition of Dana's C. grciciUs is based on a supposed 

 identification of a figure of a male ; but Dana's (9) figures would 

 apply equally well to any one of these specimens, and I do not 

 think that there are any giounds for regarding his description 

 as valid. 



The proportional length of abdomen and furca in these speci- 

 mens was 7 : 3 ; in one of Dana's figures of 0. gracilis it is 3 : 2 and 

 in the other 4 : 2. Cleve (2) has given figures of the male of 

 C. gibbula, which agree fairly well with my specimens, except 

 that the width of the abdomen is greater in his figures. He 

 states that the propoi-tion of abdomen to furca is 2:1, but in one 

 figure shows it as 9 : 5, and in the other as 8:3, so it is possible 

 that he may have been dealing with more than one species. 



The figures (PI. XI. figs. 8, 9) are taken from a specimen of the 

 larger form. 



Genus Coryc^us. 



Of the genus Corycceus, as restricted above, there is a 

 considei'able number of more or less well described forms, which 

 may be conveniently summarised under the grouping adopted 

 by Dahl. 



Of the forms with a very long furca, a convenient but hetero- 

 gd^neous group, Giesbrecht has figured C. longistylis and C.furcifer, 

 while C. lautus of Dana is easily recognised from his figure. 



The species of which the females have a one-jointed abdomen 

 are, according to Giesbrecht, C. alattis, C.flaccus, and C. elongatns ; 

 to them Dahl adds C. limbatus of Brady, originally described 

 from a male. 



Cm'ycceus rohustus stands alone in having the end claw of the 

 2nd antenna elongated in both sexes. 



Of the forms without setae on the genital segment of the 

 female, all of comparatively large size, Giesbrecht has dealt with 

 C. sjieciosus, C. dance, and C. ovalis, while Dahl accepts as a 

 valid description the C vitreus of Dana. 



The remaining species, which do not fall into any of the above 

 groups, are mostly of very small size. They all have setfe at the 

 genital pores of the female abdomen, and may be divided into 

 two groups according as the endopodite of the fourth foot bears 

 one or two setse. Of the first group C, obtusus, C. gracilicaudatus, 

 and C. venustus ha%'e been figured by Giesbrecht ; C. minutus, 

 C catus, and 0. paciiicus have been described, in his synoptic 

 table, without figures, by Dahl, who also admits C. lattis of Dana 



