78 MR W. TURNER AND DR H. S. WILSON ON THE 



Female (figs. 1, 2). — This is evidently one of the largest of the Lerneadse. It 

 presents decided indications of being divided into two gi'eat segments, — an ante- 

 rior, or cephalo-thoracic, and a posterior or abdominal. The division is indicated 

 by a well-marked constriction or neck. Immediately in front of this neck a pair 

 of long arms arise from the sides of the cephalo-thorax. 



The cephalo-thorax in a fully grown specimen is y\ths of an inch in length. 

 It projects almost at a right angle from the anterior extremity of the abdomen. 

 It is elongated, and somewhat compressed laterally. On its dorsal surface, about 

 the junction of the anterior and middle thirds, a pair of antenme is situated 

 (figs. 3, b). Their l)ases are partially concealed, and connected together by a 

 crescentic fold of the chitinic integument of the animal, the convexity of which 

 fold is directed backwards. Each antenna is 3-jointed: the basal segment short 

 and broad ; the second much longer ; the terminal smaller, and possessing a pair 

 of hooks at its free end (fig. 5). 



In front of the antenna^ and therefore close to the anterior extremity of the 

 head, a complicated buccal apparatus is met with (fig. 3, c, fig. C). Situated 

 in the middle line is a short conical snout, at the free extremity of which a 

 rounded oral aperture exists. The animal appears to possess the power of retract- 

 ing and projecting this snout at pleasure. On each side of the snout is a short 

 stump-like process, slightly bifid at its extremity. For the due examination of the 

 structures about the mouth, the higher powers of the microscope are necessary. 

 The buccal apparatus consists of an oral aperture, of two lip-like structures, and 

 of a pair of jaws. The lower lip is strengthened by a peculiar arrangement of 

 chitinic bands, which have been represented in fig. 9, Projecting not only from 

 the margin, but also partially from the inner surface of this lip, are a number 

 of fusiform bristle-like papillae. On the inner surface of the central part of this 

 lip several very delicate, faintly transversely-barred lines pass downwards and 

 backwards as far as a chitinic bar, which stretches across the lip from margin to 

 margin. The upper lip (fig. 8) consists of two chitinic concavo-convex plates, 

 which fit into each other, their concave aspects being directed to the buccal 

 cavity. The inner plate is shorter than the outer, and bears a row of long slightly 

 undulating, transversely striped, rod -like structures, fringed at their free ends. 

 The outer plate is covered at the margin, and for some distance on its dorsal aspect, 

 by sharply pointed, conical, bristle- like papillae. The lips are supported at their 

 bases on a chitinic plate, more immediately continuous with the plates of the lower 

 lip, and to which the upper lip is apparently connected by a moveable joint. 

 This plate is so arranged as to be folded upon itself in such a manner as to 

 enclose tubular spaces (fig. 6, b), in which some of the muscles of the buccal 

 apparatus are included. 



When the lips are drawn asunder, so as to expose the buccal chamber, a 

 pair of elongated scythe-like jaws (mandibles) is seen (fig. 9). These are attached 



