200 AUSTRALIAN MALACOSTRACA. 



373. Penaeus monoceros. 



Penceus monoceros, Fabr., Suppl., p. 400 ; Latr., 1. c, p. 249, 

 Milne- Edwards, 1. c, p. 415 ; Miers, 1. c, p. 301. 



Dorsal carina not sulcate. Rostrum long, but not reaching 

 far beyond the antennary squame, ensiform straight, with 8-10 

 teeth above, the teeth extending along the whole upper margin, 

 unarmed below. Telson without lateral spines. 



Endeavour River. Eound also on the coasts of India. 



374. Penseus esculentus. 



Penceus esculentus, Haswell, 1. c, p. 38. 



Rostrum extending nearly as far forward as the distal end of 

 the second joint of the internal antennae, pointed, and very 

 slightly recurved near the tip ; its superior border armed with a 

 series of six pointed teeth, of which the most posterior is separated 

 from the next by a distance greater than the intervals between 

 the others ; its lower border armed with three or four teeth, the 

 intervals between which increase slightly in length distally the 

 most anterior being separated by a longer interval from the apex 

 of the rostrum than from its successor ; rostrum continued back- 

 wards into a non-sulcated carina, which, however, loses itself 

 before attaining the posterior border of the carapace ; on each 

 side of the rostrum a groove or sulcus, which, commencing as an 

 obscure linear depression near the tip of the rostrum, increases 

 in breadth and depth posteriorly, but becomes lost about the 

 middle of the carapace. Supra-orbital spine absent ; hepatic 

 and antennary spines present ; gastro-hepatic sulcus very deep ; 

 cervical groove obsolete posteriorly. Rami of antennules short ; 

 the internal scarcely equalling in length the two last segments 

 of the peduncle ; the external somewhat longer. Outer maxilli- 

 pedes hairy, the palp short, hardly reaching to the distal end of 

 the second joint of the endopodite. Ambulatory legs increasing 

 in length to the third, which is nearly as long as the carapace 

 and rostrum ; the fourth pair much shorter than the third, but 

 equal to the second ; the fifth intermediate in length between 

 the second and third. Eirst pair with a long acute spine on the 

 under surface of the second joint, and another on the under 

 sui'face of the third joint ; the second pair with a single spine on 



