OP THE 'POECUPrNE' EXPEDITIONS. 411 



and it extends rather beyond the bristles of the region. The basal process of the ten- 

 tacle rests on the large peduncles of the tentacular cirri, each of which has its termina- 

 tion (superiorly) rounded, and bears a tuft of bristles above, and the tentacular cirrus 

 at its inferior surface, on a special peduncle. The bristles of this group are supported 

 by a spine (which has its point near the inferior margin of the special peduncle just 

 mentioned), and are for the most part stouter, especially in the neighbourhood of the 

 tentacular cirrus, than those of the next ser es. A considerable portion of the shaft is 

 bare, the distal end having whorls of distinctly separated spines, which, from the stout- 

 ness of the bristles, have a different appearance from the same parts in the succeeding 

 forms, and which appear to typify the jointed kind of the next segment. A dense 

 tuft of very fine bristles springs from a projection near the base of the peduncle ; and 

 beneath is another tentacular process, about a third shorter than the foregoing. The 

 bristles have very slender tapering shafts with long whorled spikes. The palpi are 

 fully twice the length of the tentacle, arise immediately below the peduncles of the 

 tentacular cirri, are shorter than in Leanira, and quite smooth. At the inner edge of 

 the base of each is a short curved lamella. 



The first pair of scales are distinguished from all the others by their colour, shape, 

 and coverings, and they form a sort of prow to the anterior part of the animal ; they 

 are irregularly rounded, with two prominent frills separated by a deep groove in front. 

 The anterior margin of each frill is prolonged in the form of an ear-shaped process, the 

 inner being the longer; the latter projects forward and inward, so as to guard- the ten- 

 tacular processes and bristles of the head, and, with its fellow of the opposite side, to 

 constitute the prow formerly mentioned. The other process is dii-ected slightly out- 

 ward. The scale has a 'dense coating of grains of sand, which causes it to be of a 

 lighter hue than any of the succeeding organs. This scale therefore agrees with what M. 

 Claparede says of that of Lepidopleurus inclusus, viz. in being quite different from the 

 succeeding scales ; while the first pair in his Psammolyee scarcely differ from the others. 

 Nearly the whole of its margin is covered with a close series of short papillae — strongest 

 on the posterior and outer margin, but largest on the internal border. They are short 

 on the internal ear-shaped process in front, longer on the outer. The tips of the papillee 

 are somewhat blunt, and in the shorter ones occasionally globular, as at the posterior 

 border. To modifications of cutaneous processes the fragments of gravel and sand are 

 attached, the stalks being frequently wrinkled transversely, and generally of greater 

 diameter than the ordinary granular papillae. The second scale is irregularly reniform, 

 the larger portion being external and the hilum in front ; the anterior margin is smooth 

 from the outer angle to the inner and anterior edge of the hilum. On the inner con- 

 vexity of the scale some papillae exist, few and somewhat short at first, then longer and 

 more filiform at the inner margin of the scale. The latter has rather short granular 

 papillae as in the first scale (inner border), intermingled with more slender and much 

 longer forms ; the posterior border is furnished with both kinds, and also has very 



VOL. IX. — PAET VII. January, 1876. 3 k 



