i26 DISCOVERY REPORTS 



Echiniphimedia echinata (Wlkr.). 



Walker, 1907, p. 28, pi. x, fig. 16. 



Chevreux, 1913, p. 118. 



Barnard, 1930, p. 361, fig. 23 (nodosa, turn Dana). 



Occurrence: 1. St. 140. South Georgia. 1 $ with embryos 26 mm. 



2. St. 148. South Georgia. 1 $ 19 mm. 



3. St. 149. South Georgia. 833 13-17 mm., 5 $? 15-20 mm., 1 $ with embryos 

 27 mm., 1 juv. 8-5 mm. 



4. St. 190. Palmer Archipelago (90-130 m.). 1 <J 16 mm., 1 ovig. $ 23 mm. 



Remarks. Compared with the Terra Nova specimens, the present lot are remarkably 

 uniform in their armature. Peraeon segments 1-6 and side-plates 1-3 quite smooth. 

 Lateral carina, formed by the overlapping lower margins of the segments, prominent 

 and indicated even in the young taken from the brood-pouch. Denticles on 2nd joints 

 of peraeopods 3-5 increasing in number with age from three to five or seven. The tufts 

 of sensory filaments on antenna 1 are usually better developed and more prominent, in 

 both sexes, than in Walker's figure. 



As shown above I have now followed Stebbing in his interpretation of Dana's nodosa, 

 and keep echinata as a separate species. The essence of the distinction between the two 

 forms is the presence of paired dorsal processes in nodosa, and their absence in echinata ; 

 in the latter form consequently the medio-dorsal carination assumes a greater pro- 

 minence. A profile drawing such as Dana's would apply to both forms ; hence the im- 

 possibility of an absolutely certain determination of nodosa in the absence of Dana's 

 type. Dana's figure shows denticles on the sides of the pleon segments as in echinata, 

 but the 2nd joints of peraeopods 3-5 as in the form here called nodosa. 



The colour of no. 3 is given as "pale yellowish buff with faint red speckling on 

 spines of abdomen, on posterior coxal plates and on last three thoracic legs. Most of 

 the specimens were found in a sponge". 



Distribution. McMurdo Sound; south of Graham Land. 



Genus Pariphimedia, Chevr. 

 Chevreux, 1906, p. 38. 

 Stebbing, 1914, p. 358. 



The original diagnosis of this genus has already been slightly modified by Stebbing. 

 His explanation (1910, p. 584) of Chevreux's figure of the mandible is obviously correct, 

 and is confirmed by the present specimens in which there is not a trace of a secondary 

 cutting-plate in either mandible. 



There is also a minute unguiform 4th joint in the palp of the maxilliped, situated on 

 the outer margin and not extending to the apex of the 3rd joint. 



The statement in the original diagnosis that "le telson est echancre" was apparently 

 a misprint, but it is literally true; all the present specimens have the telson apically 

 notched, and the same is true of norma ni. 



A littoral and shallow-water genus. 



