130 [AssEivrBLY 



little swollen and lobed at the end ; median, cylindrical fur inner 

 two-thirds, outer tliird conical, delicate; basal article large, swollen; 

 in length falliug a little short of the palpi ; lateral, about one-half as 

 long as the median, fusiform ; basal articles cylindrical, a little 

 longer than that of the median antenna. 



Palpi smooth, very changeable in form, at rest a little longer than 

 the median antenna, tapering uniformly to near the end, where the 

 diameter suddenly diminishes. 



Tentacular cirri with cylindrical basal articles; superior about the 

 length of median antenna; inferior but little shorter tluin superior; 

 these cirri, together with the dorsal and anal cirri, have the same 

 structure, in all respects, as the median antenna, but the dorsal cirri 

 are a trifle longer than the superior tentacular cirri, and the anal 

 are a little longer than the dorsal. 



Elytra, first pair (fig. 5) nearly circular ; the rest (fig. 6) reniform ; 

 covering the body completely in front, but further back not quite 

 touching along the middle line, leaving a narrow, naked, median 

 space; when magnified, seen to be covered with minute granules, 

 around each of which is a circular depression ; outer margin fringed; 

 from two to seven rather stout, cylindrical papillae arising from the 

 surface, near the posterior margin ; last seven segments without elytra. 



Feet (fig. 2) of the usual form, margins of both dorsal and ven- 

 tral rami with flattened somewhat triangular prolongations; ventral 

 cirri arising at about the outer third and projecting a little beyond 

 the foot, sparsely covered with papillse similar to those found on the 

 superior cirri. 



Setae of dorsal ramus quite stout (fig. -i), numerous, about half as 

 long as the ventral sette, although the longest dorsal are as long as 

 the shortest ventral ; those of the ventral ramus (fig. 3) long, 

 numerous, ending in a single curved point. The dorsal set?3 are 

 usually more numerous than in fig. 2, very nearly concealing the 

 prolongation of the ramus. 



Color. Head, flesh-color; palpi, brown, with white tips; an- 

 tennae and all superior cirri with one or two black rings at about the 

 outer third ; elytra extremely variable ; they may be white, yellow or 

 flesh-color, with markings varying much both in form and extent, 

 and in color from light brown to very dark brown ; on one specimen 

 the elytra were light orange, with transverse linear markings of dark 

 brown, on the anterior segments ; body usually white above, with- 

 out markings, or with transverse lines or spots of black or purple ; 

 the last segments have usually black markings ; the ventral surface 

 may be white, or white tinged with red or purple. 



This species is very fragile, readily breaking up and losing their 

 elytra when disturbed. Middle third widest; last third tapering 

 rapidly ; first third slightly tapering. 



Length of adult specimens, 25'"'"'; width, 4-6"^°'. 



Common, associated with Lepidonotus squamaius, and like that 

 species abundant on beds of Mytilus edulis. 



