DESCRIPTION OF SPECIES 3S9 



sutures, a fact which is not mentioned by either Beddard or Chilton, neither does the latter 

 show them in his figure of the entire animal : nevertheless they are quite distinct in the 

 specimens at the British Museum. 



The coxal plates of the seventh thoracic somite extend backwards to just beyond the 

 base of the uropoda. The pleural plates of the second and third abdominal segments 

 project only slightly beyond the anterior margin of the terminal segment. The latter is 

 broader than long, its broadest part being at the base of the uropoda, from which point 

 it narrows rapidly posteriorly and terminates in a truncate extremity: it bears, on its 

 dorsal surface, a longitudinal median carina on either side of which is a lateral sub- 

 marginal ridge which extends to just beyond the base of the uropoda, at which point the 

 two are united by a transverse curved ridge. 



Occurrence. Bass Strait, Gulf St Vincent, and St Francis Island, South AustraHa. 



37. Serolis pallida, Beddard. 



S. pallida, Beddard, 1884 a, p. 335 ; 1884 b, p. 74, pi. vii, fig. i, pi. viii, figs. 6-16; Whitelegge, 1901, 

 p. 236. 



Diagnostic characters. This species is described by Beddard from two specimens, 

 a male and a female ; the latter is the larger and measures 16 mm. in length and 13 mm. 

 in breadth. 



The body is oval, smooth, and of a pale brown colour. The head is almost triangular 

 with the apex directed backwards; a long, slender rostrum is present and the eyes 

 are small. The antennules and antennae are of approximately equal length; the first 

 peduncular joint of the former bears three strong tubercles on its upper surface and 

 a tubercle with its apex directed backwards is present on the posterior border of the 

 second joint ; the filament consists of twenty-four joints each of which bears two sensory 

 hairs. The fifth peduncular joint of the antenna is much enlarged; the filament is short, 

 consisting of only nine joints. The tergum of each of the third, fourth and fifth thoracic 

 somites is produced in the mid-dorsal line to form a backwardly directed spine ; similar, 

 though smaller spines also occur on the abdominal segments. The tergum of the sixth 

 thoracic somite is very narrow, whilst the middle portion of the seventh has disappeared. 

 The coxal plates are short and closely applied together. The terminal segment of the 

 body is roughly hexagonal in outHne with a median dorsal keel ; its posterior extremity 

 is notched. 



After examining Beddard 's specimens at the British Museum, I can only add to his 

 description that the first three free thoracic somites have their coxal plates marked off 

 from the terga by distinct sutures, and that the pleural plates of the abdominal segments 

 are short and only extend for a short distance beyond the anterior margin of the terminal 

 segment ; the coxal plates of the seventh thoracic somite extend posteriorly for a short 

 distance beyond the pleural plates. 



Occurrence. Off Port Jackson, Sydney, 30-35 fathoms. 



14-2 



