MAORURA. SCHMITT. 363 



at times common in the Sydney market, but is irregular 

 in its appearance: during the summer and autumn of 

 1891-92 it was exceptionally plentiful, since which time 

 but few specimens have been observed: Dr. Haswell is 

 mistaken in saying that this species is 'the common edible 

 Prawn of Sydney, Newcastle, etc.' 



"This is a marine species and is taken principally, 

 if not entirely, on clean, sandy beaches. It does not mix 

 with other Prawns, but from its preference for the same 

 class of ground sometimes occcurs in company with P. 

 catialiculatHi* \=P. plfbcjux]." 



Remarks. De Man takes this species "to be closely 

 related to P. caniuiinn (as described by him, loc. cit., 

 1911, p. 101), but to differ by its very short antennular 

 flagella." However, just as he notes an apparent dis- 

 crepancy in the length of the antennular flagella between 

 Dana's description of P. cariiiatus, and the specimen he 

 takes to be that species, so I find a similar difference 

 between Harwell's description of P. csculentus and the 

 "Endeavour" specimens before me. In a co-type from 

 Port Jackson, which I have been enabled to examine 

 through the courtesy of the Australian Museum, but one 

 of the four autennular flagella are present, the right 

 outer one, and of this but its basal portion, which, lack- 

 ing the slender, thread-like terminal filament, is just as 

 long as the last two joints of its peduncle. In fact, in 

 none of the species of Peneus (NCHXII- strict u) which I have 

 examined in connection with this paper are the 

 antennular flagella shorter than the last two segments 

 of their peduncle. 



Aside from the presence of a small but well-developed 

 exopodite on the fifth pair of legs, there are other more 

 or less striking differences, though possibly of less diag- 

 nostic value, separating P. csculentus from P. carinatus. 50 

 (I) The midrib of the rostrum in the former is quite 

 straight throughout its length except for a slight upturn- 

 ing of the tip ; in the latter there is an evident rise in 

 the midrib just before reaching, and above, the orbit, 

 which with its ascending extremity gives the rostrum 

 its "distinct double curve" (described by Alcock 51 for his 

 P. seniisulcatus, P. carinatux) ; (2) as a result of 



50 De Man, loc. cit.. 1911, p. 101. 



51 Cat. Indian Decapod Crust., 1906, pt. iii., fasc. i., p. 10, pi. i., 

 fig. 2. 



