298 0. 0. SARS, 



provided with small recurved liooks (see fig. 1 5). By the aid of these spines, 

 which meet the corresponding ones on the adjacent pleopod, both are bound 

 together, so as only to be admitted to move simultaneously. The rami, which 

 issue close together from tht> outer corner of the basal part, are turned ob- 

 liquely inwards, and are divided into numerous short articulations, each 

 carrying a pair of long natatory setae. 



The 2 anterior pairs of uropoda (PI. XX, figs. 9, 10, 11) are essentially 

 of the sanu! structure, though rather different in size, the 1st pair being much 

 the larger. They are rather strongly built, with both the basal part and the 

 rami coarsely spinous. In the 1st pair (fig. 10) tlie basal- part is nearly 

 twice as long as the rami, and armed in the distal part of the inner edge 

 with 4 very strong spines, the outer edge being minutely spinulose through- 

 out. The rami are subequal and narrowly rounded at the tip, each carrying 

 from 17 to 18 spines, which are more densely crowded on the outer edge, 

 those issuing from the tip being longer than the others. In tlie 2nd pair 

 (fig. 11) the basal part is but little longer than the rami, and, like the latter, 

 has a smaller number of spines. 



The last jiair of uropoda (fig. 12) are very unlike the preceding ones, 

 and I'ather small, scarcely reaching beyond the basal part of the 2nd pair. 

 They are simple, not biraraous, being composed of 2 joints of about (upial 

 size, the latter of which is somewhat lamellar and oval in form, being clothed 

 at the obtusely rounded tip witii a dense brush of slender bristles. 



The telson (fig. 13) is nearly twice as broad as it is long, and somewhat 

 narrowed distally. Tiie tip is entire and almost transversely truncated, being 

 flanked on each side by a projecting vertical crest, which is divided into 4 

 small recurved teeth, best seen in a lateral view of the animal (see fig. 14). 

 No doubt, this peculiar structure of the telson, which seems to be common 

 to all the species of the genus, may stand in some connexion with the tubi- 

 colous nature of the animal, serving in all probability to affix the animal 

 within its tube. 



Colour. — As in most other species, the body is ornamented with a dark 

 brown pigment, which is pretty well observable even in specimens for a long 

 time preserved in spirit. This pigment is (see PI. XX, figs. 1 and 2, PI. XXI, 

 fig. 1) chiefly restricted to the dorsal face of the animal, forming on the 

 cephalon a distinctly defined dark longitudinal band, which expands in front 

 so as nearly to occupy tlie whole breadth of the cephalon (see PI. XXI, fig. 1). 

 On the mesosome the pigment forms in each segment 2 more or less distinct 

 transverse bands, which are confluent in the middle of the dorsal face. In 

 the metasorae and urosome the pigment is generally more irregularly dis- 

 tributed. Moreover, some of the appendages of the body are more or less 



4>ii3.-MaT. CTp. 206. 24 



