CETJSTACEA OF THE MEEGTTI AECHIPELAGO. 77 



p. 283, pi. xvii. fig. 8 ; Alph. Milne-Edwards, Archives du Museum Hist. 

 Nat. 1861, t. X. p. 364, and Nouv. Arch, du Museum Hist. Nat. 1873, 

 t. ix. p. 165, pi. iv. fig. 5. 



One female specimeu was collected at Elphinstone Island. 



The distance between the points of tte third antero-lateral teeth, 

 which we may call the breadth of the carapace, measures 61 millim., 

 and the carapace is 39 millim. long. When comparing this 

 specimen with the individuals described above as Thai, prymna, I 

 observed the following differences : — The frontal lobes are more 

 prominent in T. spinimana, and are separated from one another 

 by much, longer and broader fissures, and the internal lobes of 

 the upper orbital margin are still more arcuated. The median 

 frontal lobes are nearly quadrangular, the second tooth is a 

 little broader and separated from the median by a fissure which, 

 appears shorter (less deep) than that by which the two median 

 teeth are separated from one another. The third frontal tooth 

 extends a little more forward than the others, and is also a little 

 narrower ; the outer frontal lobes (the internal lobes of the upper 

 orbital margin) are still more arcuate and curved than those of 

 Thai, prymna. 



The ridge on the basal joint of the outer antennae is armed, 

 with three or four black-pointed acute spines, of which the 

 two internal are united at their base ; they are partially seen 

 between the internal arcuate lobes of the upper orbital margin 

 and the third frontal tooth. The five antero-lateral teeth of the 

 carapace are nearly equal and successively decrease in length, so 

 that the fourth tooth is a little shorter than the third, but still 

 slightly longer than the fifth. 



The chelipedes are armed with more spines than those of 

 Thalamita prymna. The anterior margin of the arms presents 

 five spines, of which the proximal and distal ones are, however, 

 very small. The wrist bears a strong acute spine at its internal ' 

 angle, and the outer surface is armed with six spines of different 

 sizes. The subequal hands are comparatively less high, and 

 therefore appear more slender than in Thai, prymna ; they are 

 armed with eight or nine spines, arranged in two rows on the 

 upper margin, and the outer surface presents the same longi- 

 tudinal granulated crest which is found in the Mergui specimens 

 of T. prymna, but which is absent in individuals from near Djedda 

 in the Eed Sea, which I propose to refer to Thai, picta. Between 



