SYSTEMATIC REPORT 47 



Having decided to refer all these specimens to E. australis I now submit the following broader 

 definition of that species: 



1. Anterior margin of the carapace evenly rounded or showing a slight tendency to develop an 

 obtusely rounded median angle ; the whole anterior margin markedly convex with an average ratio of 

 length/breadth 0-3 (the breadth was measured at the deepest point before the margin curves forward 

 towards the antero-lateral angles ; the length was measured from the mid-point of this distance to the 

 middle of the anterior margin). 



2. Antennular peduncle robust; third segment articulated obliquely with the second, its inner 

 margin sinuous, considerably longer than the distal margin and produced at its distal end into a strong 

 setiferous lobe. 



3. Antennal scale only very slightly longer than antennular peduncle; twice as long as its greatest 

 breadth; showing marked sexual dimorphism — the outer margin in males and young females sinuous, 

 very convex proximally, becoming concave in the middle of its length and less concave distally; in 

 adult females convex proximally, thence almost straight to its distal end. Distal segment in both 

 sexes about half as long as broad at the base; apex asymmetrical. Antennular peduncle relatively 

 larger in males than in females (Fig. 4C). 



4. Eyes robust, about half as broad as long; cornea terminal with its proximal margin either 

 straight or very slightly oblique (Fig. 4C). 



Table 3. Measurements of seventy individuals to compare those characters given by Hansen 

 for the separation of E. australis and E. major 



5. Endopods of 2nd~4th thoracic appendages long and slender; more robust than in ungniciilata 

 and grimaldii but much longer and more slender than in sculpticauda ; 4th pair the largest with carpo- 

 propodus more than three times as long as broad, its inner margin concave for the distal third of its 

 length forming a depression into which the strong long dactylus and nail fold; third and second pairs 

 progressively smaller and their nails relatively smaller. 



6. Distal segment of exopod of uropod about as long as broad at its base (Fig. 4D). 



7. Telson with narrowly rounded apex armed with a pair of long spines; proximal third of lateral 

 margins unarmed; middle region armed with a few widely spaced spines; distal portion armed with 

 many spines arranged in series composed of 5-9 long spines with small, slightly graduated spines in 

 the spaces between them. The number of small spines occupying the distal space usually 9-18 but 

 there may be fewer; slightly graduated, becoming progressively larger distally (Fig. 4D). 



8. Size : Females are usually sexually mature at a length of about 50 mm. but specimens have been 

 recorded up to nearly 70 mm. 



Both Nouvel (19426) and Fage (1942, pp. 43, 58) have described very interesting secondary sexual 

 characters in the armature of the thoracic sterna in species of the genus. Fage in the same work made 



