328 HARMOTHOE SPINIFERA. 



Habitat. — Several examples were dredged in 6 to 10 fathoms, amongst tangle-roots, 

 in Bressay Sound, Shetland, classic ground to marine zoologists since the days of Edward 

 Forbes. A form apparently identical occurs in the British Museum, from chinks in the 

 rocks, Polperro, Cornwall. The same form is found in the Adriatic. 



Length about seven-tenths of an inch. 



The head (Plate XXVIII, fig. 3) is elongated from before backward, and since the 

 large anterior pair of eyes are carried outward, almost at the tips of the peaks, beneath 

 which they are placed, and are visible from the dorsum, the condition is diagnostic. 

 They are, moreover, wider apart than the posterior pair, and look forward and outward. 

 The smaller posterior pair are dorsal, situated near each other, and almost touch the 

 nuchal collar (in spirit). The two pairs of eyes are thus separated by a long antero- 

 posterior interval. The median tentacle has a broad base, a brownish column, a pale tip 

 with little or no enlargement beneath, and well-marked clavate cilia. The lateral ten- 

 tacles are inferior in position, small, subulate, and with similar clavate cilia. The 

 tentacular cirri are also brownish, furnished with numerous clavate cilia, and slightly 

 enlarged below the filiform tip. The palpi are brownish, with rows of small blunt papillae, 

 which are sometimes bifid at the tip. 



The body, which consists of thirty-seven segments, is comparatively short and of 

 more uniform diameter than usual, being only a little narrowed anteriorly, and somewhat 

 more posteriorly. Transverse markings occur on the dorsum between the scale-pedicles 

 and their homologues. No pigment remained on the dorsum in the preparations, though 

 it is probable traces of such were present during life. On the ventral surface traces of 

 brownish pigment occur at the sides of the prominent fold in front of the mouth. The 

 lateral prominences at the bases of the feet are well marked, but the segmental processes 

 are minute. 



Scales (Plate XXXIII, fig. 4), fifteen pairs. The first are small, nearly circular, and 

 their light brownish colour contrasts strongly with the succeeding. The surface is 

 studded with short blunt spines, which are especially distinct at the outer border, where 

 there are also a few short clavate cilia. The rest of the margin is smooth. The second 

 pair are reniform, the exposed parts being almost uniformly black, with a silky sheen and 

 a smooth margin, except at the outer border, where five or six very short clavate cilia 

 occur at intervals. The short blunt spines are distributed over the posterior two thirds 

 of the surface. The third scales are also blackish with the same metallic sheen, but 

 have a few minute pale points besides the microscopic blunt spines. The pale specks 

 increase in size in the succeeding scales, and the pigment becomes paler, the posterior 

 pair, indeed, being mottled like granite. The general shape of the posterior scales is 

 irregularly rounded or ovoid, with the scar for attachment towards the anterior and 

 outer border. The penultimate and last' pairs are much elongated from before back- 

 wards. The number of the minute blunt spines diminishes posteriorly, so that they are 

 chiefly confined to the outer border, where an occasional short clavate cilium is observed. 

 The definite pale areas are due to the absence of pigment in the areola of the epiderm 

 (hypoderm), while in the dark parts each areola is deeply pigmented. If the P. spinifera 

 of Ehlers is the same form the scales had a greyish- violet sheen. 



