130 [ASSEMBLT 



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

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

 in length falling 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 dimi-nishes. 



Tentacular cirri with cylindrical basal articles; superior about the 

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

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

 structure, in all respects, as the median antenna, but tlie 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 papillas similar to those found on the 

 superior cirri. 



Setse of dorsal ramus quite stout (fig. 4), numerous, about half as 

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

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

 numerous, fending in a single curved point. The dorsal setae 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 squamahis, and like that 

 species abundant on beds of Mytilus edulis. 



