| OCR Text |
Show 14 MR. E.J. M1ERS O N [Jan. \o, of the Brititish Museum (E. W. H. LLoldsworth, Esq.), but simple, flattened and compressed, articulated with the preceding joint in the middle of its dorsal margin, and with the terminal joint at its distal extremity (see the figure). The carapace, as usual in the genus, is laterally compressed, with the cervical suture strongly defined, the rostrum trispinose, the lateral a little shorter than the median spines. Of the segments of the postabdomen, the first, second, and sixth are longest, the sixth about as long as the two preceding segments taken together, whereas in the specimen referred to C. tridentata in the Museum Collection the sixth segment but little exceeds the fifth in length. The terminal segment is small, slightly transverse, and subtruncated at its distal extremity. The eyes project very slightly beyond the median spine of the rostrum and are bluntly pointed at their inner and distal angles; the corneee are small and placed on the dorsal surface of the peduncles. The antennules are less than half the length of the antennae ; the terminal joint of the peduncle very slightly exceeds the penultimate joint in length ; the inferior of the two flagella is fringed with long hair on its lower margin. The antennae are about twice the length of the carapace ; the antepenultimate peduncular joints bear a small spinule at the distal extremity on the outer margin ; the penultimate and terminal joints are sub-equal. The left chelipede is the larger ; the merus-joint is less than twice as long as broad, and its inferior margin is acute and serrated, but without strongly developed teeth or spines. The carpus is rather shorter than, but as broad as, the palm, smooth, its inferior margin acute and entire; palm rather longer than broad, smooth and polished, with the upper and lower margins fringed with hair, the lower margin acute ; several tufts of seta occur on its outer surface near to the base of the fingers, which are shorter than the palm, with the tips incurved ; the uppermost arcuated, with the inner margin acute and entire, the lowermost with a small tooth or lobe on the inner margin, both clothed on their outer surface with several tufts of hair. In the smaller chelipede the joints are all much slenderer, and the merus-joint is not serrated on its inferior margin. The third legs have the antepenultimate joint armed with a low triangular lobe on the inferior margin; the produced posterior lobe of the hairy penultimate joint is broad and obtuse ; the dac-tylus small, hairy, and subacute. lines. millim. 3. Length of the body, nearly 22 46 Length of larger chelipede, nearly.... 12| 26 In the specimen in the Museum Collection referred to G. tridentata, v. Martens, there is a strong tooth or lobe at the proximal end of the inferior margin of the merus of the larger chelipede. Nothing is said as to the existence of this lobe by v. Martens : but Milne- Edwards, in his monographic revision of the genus Callianassa\ describes C. tridentata as having the merus unarmed. 1 Nouvelles Archives du Museum, v. p. 101 (1869). |
