| OCR Text |
Show 546 DE. J. G. DE MAN ON CRUSTACEANS [Dec. 12, tooth. The short flagellum of the internal antennae, which is just as long as their peduncle, is serrulate internally, and coalesced for a very short distance, i. e. for ^ of its length, with the outer flagellum. The legs of the first pair reach with their chelae beyond the antennal scales; the chela is a little more than half as long as the carpus. The legs of the 2nd pair (figs. 8 and 9) are unequal, the left being a little larger than the other. The left leg (fig. 8), which is somewhat shorter than the body, projects more than half the carpus beyond the antennal scales. The cylindrical merus, that slightly thickens distally, is four times as long as thick. The carpus, which is a little shorter than the merus, has a rather stout, conical shape; it thickens considerably towards the distal end, appearing here more than twice as thick as at its base, when looked at from above, and its width at the distal end measures two-fifths of its length. The chela is somewhat longer than merus and carpus taken together. The palm is nearly once and a half as long as the carpus, and one-fourth longer than the fingers, which are a little curved inward, so that the inner border of the chela appears somewhat concave ; the palm, distinctly broader than the carpus, is somewhat broader than thick, though but very little, the breadth in the middle being in proportion to its thickness as 15 : 13, so that it appears almost cylindrical. About at one-third of its length from the articulation the immobile finger is armed with a conical tooth (fig. 10 ), half as high as the finger is broad at this place; behind it is seen a smaller rounded tooth and, between the latter and the articulation, four or five extremely small and low rounded teeth. The dactylus appears, at its base, a little broader than the fixed finger (fig. 8), and is armed, just in the middle, with a slightly curved, conical tooth, which is a little larger than the foremost tooth of the index; opposite to it on the fixed finger is a small notch (fig. 1 0 ), that fits the tooth. Between this tooth and the articulation there are still five or six, much smaller, obtuse, somewhat unequal teeth. The tapering fingers therefore do not shut close together; between the foremost teeth and the tip the cutting-edge is sharp. The joints of this leg are everywhere covered with innumerable minute, sharp spinules, except on the usual, naked lines; these spinules are more crowded and a little larger on the outer and on the inner border of the palm and near the finger-cleft on the upper surface, whereas they are less numerous on the rest of the upper and on the lower surfaces. They are few in number on both sides of the fixed finger; on the outer margin of this finger they are also few in number, but larger than on the inner border of the palm. The outer side of the dactylus is thickly beset with slenderer, larger spinules, the sharp tip of which is curved upward, whereas the inner part of the upper and lower surface is nearly smooth. A few microscopical hairs occur on the outer and inner borders of the chela and of the other joints. |
