208 



THE VOYAGE OF H.M.S. CHALLENGER. 



edges are armed in tlieir outer part with numerous small denticles, and Lave moreover, 

 near the base, on either side, three somewhat coarser denticles placed at some distance 

 from the rest. The apex (fig. 23) is abruptly tnnicate, and bears six rather strong sjiiues, 

 the innermost pair the largest, and, between the latter, three very small denticles occur, 

 besides two rather long and delicate setse (omitted in the figure). 



The uropoda (fig. 24) are rather large, projecting considerably beyond the telson. 

 The inner plate is nari'ow lanceolate, with the auditory apparatus very fully developed, 

 and the inner edge, beneath the marginal setae, densely spinose. The outer lAate is 

 appreciably shorter than the inner, but rather broader, with the exterior edge armed, in 

 front of the terminal linguiform articulation, with about six spines, increasing in size 

 posteriorly. 



As regards colour, the animal, according to Dana, is in a living state almost colourless, 

 though sometimes purply along the ventral face of the tail, and tinged with red at the 

 sides of the anterior division (the marsupial pouch). This purjilish and reddish colour is 

 found to arise from stellate pigmentary deposits distrilnited with great regidarity and 

 still retained in the specimens preserved in spirit. Thus, along the ventral face of the 

 tail is seen (figs. 1, 2, 3) on each segment a median and two lateral pigment-spots, 

 the one occurring at the end of tlie last segment being considerably ramified. On the 

 two posterior exposed segments of the trunk, similar pigment-spots may be seen, and 

 on either side of the marsupial pouch in the female (fig. 2), an exceedingly ramified 

 reddish pigmentary deposit may wdth facility be discerned. Moreover, at the inner side 

 of the anteunular peduncle, similar pigmentary ramifications occur, extending to a 

 greater or less distance even into the inner flagellum. 



Habitat. — All tlie specimens in the collection were taken at the surface of the sea. 

 The following is a list of the localities, with dates appended : — 



