158 RECORDS OF THE AtJSTRALIAN MUSEUM. 



posteriorly the set;e are few or wanting. The spines are disposed 

 as follows: three equally spaced in a median line, the first situated 

 at the base of the rostrum, the second and third on the gastric 

 region. There is a spine immediately posterior to each orbit, and 

 another on each side, situated at a short distance inwards behind 

 the latter and in a line with it and the anterolateral angle of the 

 carapace. There are five or six submedian pairs ; the first are 

 seated on the gastric region and are rather widely separated, the 

 remaining pairs are arranged in the form of a narrow V on the 

 cardiac area, with a single median spine at their base ; a few 

 occur on the branchial i-egion in a line with the inner orbital 

 prominence, and about ten form a transverse series at a short 

 distance from the hinder margin of the carapace. 



Lateral margins of the carapace armed with fourteen or fifteen 

 more or less compressed spines ; of these, five are in advance of 

 the cervical incision, the anterior one is large and prominent, the 

 succeeding four gradually diminish in size as the well-marked 

 cervical groove is approached, the latter is bounded posteriorly by 

 a spine equal to or larger than that at the antero-lateral angle, 

 the eight following are subequal in size and in distance apart, 

 their outer borders are beset with tubercles. An irregular sub- 

 marginal series of spiniform tubercles is situated on the posterior 

 half of the carapace immediately above the lateral margin ; these 

 form one or two rows and are most pronounced posteriorly. 



A sharply defined, deep, smoothish, transverse groove extends 

 from side to side across the hinder part of the carapace, at a 

 distance of about 7 mm. from the ciliated posterior margin ; 

 laterally the groove is nearly twice as wide as at the centre. 



Pleon strongly sculptured, clothed with setiferous tubercles. The 

 first segment is evenly convex above and below, and exhibits 

 superiorly a well-marked transverse groove, situated much nearer 

 the posterior than the concealed anterior margin, and it descends 

 on each side to the coxal plate; the latter is small and bilobed. 

 The anterior lobe is broad, rounded, and its margin is continued 

 inwards to the end of the transverse groove ; the posterior lobe is 

 triangulate and acute, its point is directed outwards and down- 

 wards ; the posterior margin is slightly crenate and oblique. 



The second to sixth segments bear raised arborescent markings; 

 all, except the last named, have a median carina. Each segment 

 is transversely grooved and somewhat depressed anteriorly ; the 

 groove is bounded by a raised crenated line, which is just visible 

 on the first three, but cannot be seen on those succeeding without 

 bending the pleon downwards. The inner process of each coxal 

 plate is limited by a well defined smooth groove, which extends 

 from the anterior depression to the articular condyle. 



The inferior surface of the second segment is much less curved 

 than the first ; the convexity diminishes to the fifth, which is 



