406 ONUPHIS BRITANNICA. 



or stellate black mark is found toward the inner edge of each dental plate. Certain 

 differences exist between the foregoing and that figured in the ' Challenger '—it may 

 be from difference in age. In one example the maxillas had been reproduced (Plate 

 LXV, fig. 13), both sets being visible in the preparation. No sign of duplication in 

 the posterior appendages is present. 



The first foot is long and slightly tapered — with a bulbous extremity — bearing a 

 subulate dorsal cirrus about its middle dorsally, and having toward its tip dorsally a 

 long and rather stout papilla. A stout subulate process (ventral cirrus) occurs near 

 the base ventrally. The foot is supported by a series of strong yellow spines, and, 

 though the tip of only one bristle projects beyond the skin, others are included in the 

 tissues. These consist of large falcate bristles with bifid tips, furnished with wings 

 (Plate LXXXIV, fig. 3). In the second foot two of these project beyond the tip of the 

 foot, and the dorsal cirrus is longer, its tip reaching beyond that of the foot. The 

 terminal papilla is also longer. This foot is smaller than the first. 



The third foot is shorter, but is likewise directed forward and outward, and it differs 

 from the foregoing in the longer dorsal cirrus, and in the short lobate condition of the 

 ventral cirrus, which is thus homologous with the ventral pads which occur at the bases 

 of the feet behind. The foot is considerably diminished in size, the dorsal cirrus is very 

 long, and the distal papilla extends far beyond the tip. Dorsally the setigerous lobe bears 

 simple and brush-shaped bristles, and below these the tenth foot has dorsally the subulate 

 dorsal cirrus, from the inner base of which the first branchia arises as a somewhat broad 

 crenate process which varies in length according to the example; some having short 

 processes, others having a branchia about as long as the dorsal cirrus and occasionally a 

 spur appears on it toward the tapering distal end. The setigerous region is bluntly 

 conical with a stout papilla projecting in front of the bristles anteriorly, whilst posteriorly 

 is a longer subulate process or papilla resembling a cirrus. The ventral cirrus is in 

 the form of a pad inferiorly. Dorsally and ventrally are stout bristles with rather short 

 and finely tapered tips which have broad wings inferiorly. A few brush-shaped forms 

 are also present, and a single long hook with a bifid tip. 



The branchias thus commencing on the tenth foot continue as single filaments almost 

 to the tip of the tail. Whilst these organs form long thick processes, the dorsal cirri 

 diminish in size from before backward, the disproportion between the posterior branchiae 

 and their minute cirri being great, the dorsal cirrus, moreover, moving further up the 

 branchia in each case. 



The twentieth foot (Plate LXXV, fig. 5) presents dorsally the large branchia which 

 has absorbed the whole basal region, so that the small, slender cirrus appears as a process 

 of the branchia. The setigerous region forms a short cone with a bulbous tip. The 

 bristles are the same as in front, viz., dorsally and ventrally stout simple bristles 

 (Plate LXXXIV, fig. 3 a) with a broad wing on the short and finely tapered tip, a few 

 brush-like forms (Plate LXXXIV, fig. 3 b), and the powerful bifid hooks with wings 

 (Plate LXXXIV, fig. 3 c). 



The structure of the foot alters little posteriorly except in the proportion of its 

 parts. The brush-shaped bristles are often prominent from the absence of the tips of 

 the winged forms. 



