s 



42 "TERRA NOVA" EXPEDITION. 



none are quite so spiny as Hodgson's P. glabra. They also differ among themselves in 

 the development of the rounded or irregular dorsal prominences on the lateral processes, 

 in the sharpness of the distal corners of the first coxa, and in the extent and shape of 

 the " spinous cushion " at the base of the movable finger of the chelophores. In some, 

 this cushion is depressed and restricted to a small area at the very base of the finger, 

 in others it occupies at least half of the length of the finger, and its distal end projects 

 freely as a conical lobe as in Wilson's figure of the chela of P. forjicifer. In all the 

 females the femur is distinctly shorter than the second tibia, although the diff"ere;nce is 

 less than in the males. Mobius and Bouvier agree that the femur is equal to the second 

 tibia of the female in P. glabra. 



At the distal ends of the femur and first tibia there are three small tubercles 

 dorsally and an indistinct tubercle on each side below the lateral line. These tubercles 

 vary in their degree of development, and can hardly be detected in the specimens 

 referred by Hodgson to P. glabra ; they correspond to the five processes that are found 

 in this position in some or all of the species belonging to Loman's subgenus Rigona. 



I am not at all confident that this species can be maintained as distinct from 

 PhoxicMlidium patagonicum, Hoek (1881, p. 84, PL xii, figs. 6-9). The only adult 

 specimen among Hoek's syntypes is the female which he has figured. This difii'ers 

 considerably from all the specimens that I have referred to P. glabra. It has the 

 lateral processes separated by less than half their own diameter at the base, the 

 cephalon nearly parallel-sided as seen from above, with the ocular tubercle not 

 occupying the whole of its width anteriorly ; the chela is hardly widened distally, and 

 its outer edge is straight ; the propodus is about three times as long as wide, the main 

 claw is less than half the length of the propodus, and the auxiliaries about half the 

 length of the main- claw. In adult specimens of P. glabra the lateral processes are 

 separated at the base by a distance about equal to their own diameter, the cephalon 

 narrows toward the front, where the base of the ocular tubercle occupies the whole of 

 its width ; the chela is widened distally, and its outer edge is concave ; the propodus 

 is about four times as long as wide, the main claw is usually more than half the length 

 of the propodus, and the auxiliaries distinctly less than half the length of the main 

 claw. When, however, the comparison is extended to the immature specimens of both 

 forms, all these distinctions lose their sharpness ; in particular, the immature specimen 

 that Hoek described under the name P. jxitagonicum var. elegans (1881, p. 86, PI. xii, 

 fig. 10) appears to difi"er in no respect from specimens of P. glabra of similar size, 

 except that the lateral processes are less than their own diameter apart, the main claws 

 are a little shorter, and the auxiliaries a little longer. 



Pallenopsis pilosa (Hoek). 



Plwxichilidium pilosum, Hoek, 1881, p. 90, PI. xiii, figs. 10-13. 



Pallenopsis pilosa, Hoek, 1883, p. 9; Hodgson, 1907, p. 15, PI. ii, fig. 2; Bouvier, 1913, 

 p. 107, figs. 60 and 61. 



