DESCRIPTION OF SPECIES 333 



lateral margins, commencing from the attachment of the terminal appendages, curve 

 inwards and then slightly outwards, becoming almost parallel just before their termina- 

 tion". Colour in spirit: brown. 



Nordenstam (1933, pp. 82-5) describes a new variety of the above species which he 

 names eugetnae. It differs from the main species in the following respects : 



(i) "in its more oblong shape of body; 



(2) in that the free triangular tips of the pereion segments laterally, from their 

 spimera are lacking; 



(3) in having two lateral tuberculae on the pleotelson; 



(4) in having the triangular tip in the middle of the posterior margins of the pereion 

 segments missing on the first and second segments". 



These differences do not seem sufficient to warrant the formation of a new variety ; 

 consequently I have placed the name in the synonymy of S. mimita. 



Occurrence. Port Philip, Australia, 38 fathoms; and off St Francis Island, from 

 6 to 13 fathoms. 



25. Serolis bakeri, Chilton. 



S. bakeri, Chilton, 1917, pp. 398, 399, figs. 12-14. 



Diagnostic characters. This species, according to Chilton, bears a close resemblance 

 to S. mimita, Beddard, but specimens are slightly smaller than those of the latter species, 

 the largest breeding female measuring 6 mm. in length and 5 mm. in breadth : the males 

 are approximately the same size as the females. 



As in S. mimita three rounded tubercles are present on the posterior margin of the 

 head, but neither the median tubercles nor the lateral tubercles which are seen on the 

 thoracic somites of the former species are found here. 



No definite information is given as to whether the coxal plates of the first three free 

 thoracic somites are separated from them by sutures ; but since sutures are present in 

 S. mimita, and Chilton, after mentioning the points in which the two species differ, 

 states that in all other respects they are alike, it is probably correct to assume that they 

 are also present in this species. 



The tergum of the seventh thoracic somite is partially fused with that of the first 

 abdominal segment, the posterior suture of the former being obsolete for a short 

 distance on either side of the middle line. The coxal plates of this somite extend back- 

 wards through the anterior third of the terminal segment and the pleural plates of the 

 third abdominal segment reach to the middle of the segment: the terminal segment 

 bears a conspicuous median keel, and its posterior extremity is narrow and rounded. 

 The uropoda are described as having " both branches narrow, outer with external margin 

 obscurely serrate, end dentate or crenate, and with one or two hairs, inner branch a little 

 longer and with end less distinctly serrate". 



Nordenstam (1933, p. 85) regards this species as a variety of S. minuta, Beddard. 



Occurrence. Encounter Bay, South Australian coast. 



