88 CHARLES CHILTON 



the male in which the second gnathopod has no triangular process on the 

 basis and differs a little in the shape of the propod. The second form of the 

 male was described as LonchoineriLS gracilis by Bate from British seas and is 

 now known to be widely distributed in all seas, while the first form does not 

 appear to have been recorded from any locality except South America, New 

 Zealand and Juan Fernandez. 



Amphithoe femorata (Kroyer). 



Amphithoe femorata Stebbing, igo6, p. 636. 

 Amphithoe brevipes Stebbing, 1906, p. 637. 



Locality. 



Masatierra, »among floating Macrocystis drifting from the continent.* 

 S. P. E. No. 598. April 1917. Three specimens, female, the largest about 

 13 mm. in length. 



I feel pretty confident in referring these specimens to Kroyer's species, 

 which was described from Valparaiso, South America. I have only female 

 specimens, but they agree very closely with the description of this species 

 given by STEBBING. A. brevipes (Dana) must, I think, be considered to be 

 the same species. The parts that are fully figured by Dana, such, for example, 

 as the antennae, are quite similar. A. brevipes as understood by Stebbing, is 

 known from the South Atlantic (Tierra del Fuego, Falkland Islands) and also 

 from the South Pacific (Valparaiso). There is close general resemblance also 

 between my specimens and A. rtibricata (Mont.) of Europe, etc. I have been 

 able to compare the Juan P^ernandez specimens with two of A. rubricata from 

 England as well as with Sars' figures and though there are slight differences 

 in some of the mouth parts, etc. these do not appear to be of much importance. 

 Della Valle grouped A. rtibricata, A. femorata, A. brevipes and also A. 

 brasiliensis (Dana) together as one species under the name A. rubricata, and 

 they certainly appear to form a fairly defined group in which the extreme 

 forms will probably be shown to be more and more closely connected by 

 transitional forms as specimens from different localities are examined. 



In his description of A. femorata, STEBBING says »in many respects resemb- 

 ling Stmamphitoe pelagica.'i) When first examining my specimens before I had 

 dissected one to ascertain the presence of the mandibular palp I had indepen- 

 dently noticed the strong resemblance to this species, and indeed for the pres- 

 ence of the palp of the mandible it would not be easy to know to which of 

 these two species to refer female specimens. The palp in my specimens (fig. 

 3, A)* is small and slender, more so than in Sars' figure of ^. rtibricata. In 

 each of the two specimens of A. rubricata from England that I have examined 

 the palp of the mandible is distinctly smaller in comparison with the rest of 

 the appendage than in the figure given by Sars and is much less abundantly 

 supplied with setules, those on the third joint being nearly confined to the 

 extremity. Probably the mandible is tending to become vestigial in this group 



