ARICIA LATREILLII. 503 



muscular bands and the powerful muscles of the feet, but the dorsal and ventral 

 longitudinal muscles are less massive in proportion. Behind the middle of the body, 

 again, the great increase of the ventral longitudinal muscles is a feature of note, the 

 dorsal being comparatively small. 



The first region of the body comprises from thirty to thirty-three bristled segments, 

 the first and last being more or less modified. The strong ventral bristles of the region 

 as a rule are somewhat paler than in A. Guvieri, the stout ventral bristles of which are 

 sometimes even dark brown. 



The first segment is larger than the buccal, but less than those which follow. Like 

 the rest the foot is dorso-lateral in position, the superior division indeed being wholly 

 dorsal, and consisting of a tuft of transversely serrated (camerated) and finely tapered 

 bristles with a cirrus behind and rather towards the outer border. The ventral division 

 is dorso-lateral, and it has a cirrus and a long papilla with a group of the long tapering 

 camerated bristles, and a series of strong and short curved forms with blunt tips generally 

 smoothly rounded, and having spinous rows (abraded) on the shaft below. Many of these 

 are arranged at an angle to the longer forms, and the shorter forms are ventral. The 

 second foot has longer dorsal bristles and a longer and larger cirrus, whilst fewer long 

 serrated bristles occur in the ventral division, which has three papillae. The third foot 

 has a few tapering serrated bristles superiorly and a thinly scattered series along the rest 

 of the line. All are shorter than those in front. The stout abraded forms with the 

 rounded ends and serrations on the convex edge of the curve (as on the tapering bristles) 

 extend from the upper to the lower edge of the division. The upper papilla is longest 

 (and may represent the cirrus), and seven shorter follow. The fourth foot has still fewer 

 and shorter tapering serrated bristles, but the curved stout forms are more conspicuous. 

 The one increases in strength as the other wanes. 



The tenth foot has a much longer dorsal cirrus and a series of strong dorsal bristles. 

 The ventral division has very short tapered forms here and there along the line, the 

 whole length of which bristles with the stiff curved and serrated forms, the tips of which, 

 moreover, are more or less acute. About fifteen papillae occur along the line. The 

 twentieth foot has a longer and denser tuft of dorsal bristles, and the cirrus has increased 

 in size. The short tapering serrated bristles are still present along the line, whilst the 

 curved spine-like forms are fully developed and thicker than in front. Many of the points 

 are sharp, while others are rounded and blunt. The papillae are more numerous, and the 

 line is longer. 



At the twenty-ninth foot the dorsal cirrus has assumed the form of a bellied knife, 

 that is, whilst its inner edge (that next the branchia) is more or less straight, the outer 

 springs from a broad base, curves outward, and then backward to the subulate tip. The 

 row of the large curved yellow spines is now short, but traces of serrations are still visible, 

 and the short serrated bristles accompany them. The papillae are conspicuous, the 

 longest being* that next the dorsal division, and another a little to its exterior. 



The knife-like shape of the dorsal cirrus is conspicuous at the thirtieth foot, and so 

 is the great tuft of serrated (camerated) tapering bristles. Externally after an interval 

 is a long cirrus-like papilla, and a somewhat shorter one to the exterior. Yentralwards 

 little is seen except the row of papillae but the tips of a few tapering serrated bristles at 



