STUDIES IN AUSTRALIAN CRUSTACEA McCULLOCH. 233 



groove incomplete and forming a very shallow depression on 

 each side, but the H-shaped grooves detining the gastro-cardiac 

 regions are more distinct. No postfrontal prominences, though 

 a minute median furrow is present. The length of the ceph- 

 alothorax is 1.4 in its breadth. 



Front, orbital borders, and anterolateral margins raised into a 

 low ridge. Front detle.xed, its anterior margin slightly concave, 

 its width •i.4 in the breadth of the carapace; its anterior face 

 is deflexed downward and backward to meet the epistome. 

 Outer frontal angles rounded and continuous with the orbital 

 borders. Orbits slightly oblique, wider than deep, the margins 

 entire without sutures; the lower margin is microscopically 

 milled and forms a cristate tubercle internally, and the ex- 

 terior angle is not tooth-like. 



Lateral margins of carapace arcuate, defined anteriorly by a 

 low, smootli crest; a minute notch a short distance behind the 

 eye on each side forms an epibranchial tooth. Posterolateral 

 margins ill-defined, slightly oblique, and longer than the 

 anterolateral ; they are marked with fine wrinkles which pass 

 forward and downward to the sides of the carapace. Ptery- 

 gostomial and subhepatic regions somewhat rugose with 

 scattered ridges and wrinkles. 



Abdomen consisting of seven movable segments. The first 

 is rounded anteriorly, with concave sides ; its width is oue-sixtli 

 greater than its length. The second is wider than long, its 

 sides almost parallel, slightly convergent anteriorly. The 

 fifth, foui'th, and third joints become uniformly wider, while 

 the second and first are as wide as the fifth. Sternum and 

 abdomen with scattered punctations. Two broad and deep 

 furrows are present on the anterior part of the sternum be- 

 tween the last abdominal segment and the base of the maxilli- 

 peds. 



Basal antennal joint in contact with the under surface of 

 the fronto-orbital angle, the flagellum about two-thirds as long 

 as the eye. Epistome broad, with a broad rounded depression 

 on its median portion, which forms an angular lobe between 

 the maxillipeds. Outer maxiliipeds smooth, punctate; the 

 ischium is subquadrangular, much longer than broad, with a 

 slightly oblique groove much nearer the inner than the outer 



