284 "TERRA NOVA" EXPEDITION. 



Remarks. — To the many synonyms of this species, I think must be added E. sennae, 

 Colosi. The type specimen measures only 4 mm. , and the species is said to differ 

 from E. typica : (1) by the absence of a prominent spine on the outer margin of the 

 antennal scale ; (2) by the shorter and more rounded form of the telson ; and (3) by 

 the relative lengths of the inner and outer uropods. Zimmer (1914) has pointed out 

 that the first difference is due to innnaturity. With this opinion I am in complete 

 agreement. The smallest specimen in this collection measures 4 mm. in total length, 

 and agrees substantially with Colosi's diagnosis of E. sennae. But close comparison 

 with E. typica has led me to believe that all the differences between the two forms will 

 be found to disappear with growth. Evidence that the non-development of the spine on 

 the outer margin of the antennal scale is a juvenile character is provided by Hansen's 

 species E. pulchra, which is described from an immature specimen 5 mm. long. On 

 one side the antennal scale is provided with a prominent spine on the outer margin, 

 and on the other side the scale is more or less like that described and figured for E. sennae. 

 With this proof, the first and most serious difference between E. typica and E. sennae 

 disappears, and the other two differences are much more readily explained on the same 

 grounds. 



Distribution. — Widely distributed in both the Atlantic and Pacific Oceans, but the 

 present records represent the most southerly area in which the species has so far been 

 found. 



7. Euchaetomera ocidata, Hansen. 



E. ocidata, Hansen, 1910, p. 66, pi. X, figs, ia-e ; Tattersall, 1911, p. 125. 



Occurrence. — North of New Zealand. Station 80, one immature, 4 mm. ; 

 Station 130, one female, 8 mm. 



Remarks. — The larger specimen is considerably damaged, and the identification 

 of both must be considered doubtful. In the form of the eyes and in the degree of 

 development of the rostral plate they appear to agree with E. oculata rather than with 

 any of the closely allied species E. tenuis, E. glyphidophthalmica or E. pileheja. 



Distribution. — East Indian Archipelago (Hansen) ; Indian Ocean (Tattersall). 

 The present records therefore indicate a wide extension of its known geographical range. 



Genus PSEUDOMMA, G. 0. Sars. 



8. Pseudomma belgicae (Hansen, MS.), Holt & Tattersall. 



Pseudomma belgicae, H. & T., 1906, p. 8; Tattersall, 1908, p. 27, i± VI, figs. 1-8; Hansen, 

 1908, p. 12, pi. II, figs. 2a-c ; Hansen, 1913, p. 11, pi. 1, figs. 3a-b ; Zimmer, 1914, p. 389 ; 

 Hansen, 1921, p. 2. 



Occurrence. — Antarctic, Station 314. One male and one female, 26 mm. 



Remarks. — Both these specimens appear to be adult. The male, however, has 

 no brush of setae on the antennulary process. This may be due to the fact that they 

 have been broken off during the processes of capture and preservation. The 



