CRUSTACEA OF THE MERGUJI ARCHIPELAGO. 85 



rather obtuse. In specimens which are twice as large and 

 22 millim, broad, the frontal teeth still fully resemble those of 

 the youngest specimen. In larger individuals the frontal teeth 

 appear gradually less rounded, more triangular, and pointed, 

 and separated from one another by larger and deeper fissures, 

 though the two median teeth are changing their form a little 

 more slowly than the others, appearing obtuse, whereas the 

 other teeth are already pointed and acute. In a specimen 

 50 millim. broad the two median teeth are blunt, the second teefch 

 triangular, though still obtuse ; the third and the fourth teeth, 

 however, are very acute, especially the third. In the largest 

 specimen in the Collection, which is 63 millim. broad, all the 

 frontal teeth are sharp and acute, those of the first pair being 

 even triangular and a little pointed. The frontal teeth are 

 flattened and depressed, and the median teeth are slightly 

 more prominent than the others. The front appears to me 

 to be a little more prominent than in Q-. spinifertim ; but as the 

 figure of that species is a double enlargement made from a 

 young and small specimen, the drawing is perhaps somewhat 

 inexact. 



The orbits are of the usual size, and their upper margin presents 

 two narrow linear fissures ; the internal lobe of the inferior margin 

 of the orbits is triangular and acute, and projects scarcely as 

 much forwards as the internal angle of the upj)er margin. 

 The inferior orbital margin is also marked with a fissure or 

 hiatus. 



The antero-lateral margins are armed with six acute teeth, in- 

 cluding the external orbital angles ; the tijDs of all the teeth are 

 dark- coloured. The first two teeth are of equal size ; the third 

 is a little larger, as in G. annulatum, Fabr. ; the fourth is a 

 little smaller than the third ; the fifth is a little smaller than the 

 fourth ; and the sixth or last tooth is distinctly longer than the 

 preceding, being directed transversely outwards and slightly for- 

 wards *. In the younger specimens the last antero-lateral tooth is 

 almost twice as long as the fifth, while in the largest specimen it 



* Though the first two antero-lateral teeth are slightly smaller than the 

 third in this species, as in G. annulatum, Fabr., G. luciferum, Fabr., and G. japo- 

 iiicum, de Haan, they are, however, about as large as the fifth ; in G. orientale, 

 T)a.na,=dubiu7n, HoflPm., and in G. acutifrons, de Man, on the contrary, the 

 second antero-lateral tooth is rudimentary, being in the last-mentioned species 

 even scarcely perceptible. 



