ATTSTBALIAN HALACOSTBACA. 205 



squame ; dorsal carina arched. A strong dorsal carina on all 

 the abdominal segments, that on the sixth very prominent ; sides 

 of the segments deeply channelled, without spines at the sides ; 

 sixth segment with the postero-external angle prominent, tooth- 

 like. Telson unarmed, entire at the extremity. 



Port Denison (Mr. Alex. Morton). 



This is very probably S. sculpta of Stimpson. 



381. Sicyonia sp. ? 



Dorsal carina with three very large acute teeth, the notches 

 between which extend down to the general level of the carapace. 

 Rostrum with three teeth above ; its extremity abruptly truncate 

 and armed with three small teeth ; no teeth below. Sides of the 

 abdominal segments not deeply channelled, each with a slight 

 dorsal carina ; a very small spine-like tooth at the postero-lateral 

 angle of the fifth and sixth segments. Telson terminating in 

 three small spines, of which the median one is the largest. 

 Length 2\ in. 



Port Jackson. 



Order STOMATOPODA. 



Ophthalmic and antennulary segments free. Branchia? not 

 enclosed beneath the carapace, but pendent from the base of the 

 abdominal appendages. Carapace short, covering only the 

 segments of the head. Internal antennae with three flagella. 

 External antennas short, with a f oliaceous scale. Second pair of 

 legs greatly developed and prehensile. Abdomen large, the 

 telson and appendages of the last segment greatly developed. 



Genus Ltsiosquilla, Dana. 



Carapace not longitudinally costate, the cervical suture 

 posteriorly obsolete. Eostral plate reaching to, but usually not 

 covering the base of the eye-peduncles. The five exposed 

 thoracic segments and the segments of the abdomen loosely 

 articulated and depressed ; the latter wider than the thoracic 

 segments, and not longitudinally carinate ; mobile spines of 

 posterior margin absent or very minute. Dactylus of second 

 thoracic limbs not dilated at base, and armed internally with 

 long and usually numerous spines. \_Miers.~\ 



