| OCR Text |
Show 178 ME. A. D. MICHAEL O N A N [Mar. 5, outside their postero-lateral edges. The genital opening itself is a longitudinal slit closed by soft labia in both sexes. The epimera of the first pair of legs are fringed on the edges nearest the median line of the body by a series of beautifully feathered or pectinated hairs (fig. 6), which vary considerably; three or four at the anterior are curled over at their ends and plumose, the remainder are some finely (fig. 8) others more coarsely (fig. 7) pectinated; most of them are terminated by a long fine spine, which is not pectinated. There are a few very small, curved, colourless hairs on the epimera and the hind margin of the body. Legs (figs. 12, 13).-The legs gradually increase in length from before backward; they are entirely chitinized and entirely without swimming-hairs ; they are terminated by strong didactyle claws ; the tarsi, particularly the two hind pairs, are enlarged at their distal ends and excavated so as to form deep cups. All the legs are armed with a number of large orange-scarlet spines, or spines tipped with that colour, which form the most striking feature of the species ; they are mostly lanceolate or laurel-leaf shaped, but some are straight; the largest are arranged in radiating whorls round tbe distal ends of tbe third and fourth joints of the first pair of legs and the third, fourth, and fifth of the other pairs : there are also two large spines, one on tbe underside of the second joint of each second leg, and several similar but smaller spines on the upperside of the same joints in the first three pairs of legs and the underside of the fourth; there is also a pair at the distal end of the tarsus of the third and fourth legs, curving over and protecting the claws. There are lines of somewhat similar, but uncoloured, spines on the outer edges of the fourth coxae. There are numerous other hairs on the legs, particularly on the outer side of the fourth legs; these hairs are mostly strongly curved, colourless, soft, and diminishing to a point; there are smaller fine hairs on the tarsi. The Integument (Plate VII. fig. 11; Plate IX. figs. 23, 24, 25). This varies in thickness in different parts of the body; it may be said to consist of three layers, or it might be considered two layers, the outer being double. Treating it as three layers, the outer, which may be called the " epiostracum " (fig. 24, ep.), consists of a single row of epithelial cells, rounded or conical on the outer side, flat on the inner side; these cells form the papillae with which the soft parts of the body,, particularly the dorsal surface, are coated externally. They are loosely arranged and vary in form a good deal in different parts of the creature; those towards the anterior end being, as a rule, the most papillose. The second layer, which may be called the "ectostracum " (figs. 24, 25, ec), consists also of a single row of cells; but they are more cubical and form a dense and thoroughly united tissue w'ith a flat surface on both sides: otherwise the cells are no doubt of the same nature as those of the outer layers, the latter being more or less transformed or perishing. The inner layer (figs. 24, 25, II.), which may be called the "end- |
