10 AUSTRALIAN MALACOSTKACA. 



Upper surface of the carapace tuberculated, nearly horizontal ; 

 three tubercles on the gastric region arranged in the form of a 

 triangle, one on each branchial region; antero-lateral borders 

 with three irregular triangular teeth. Third joint of all the 

 limbs armed with a few spines, those of the second pair much 

 longer than the following. 



A widely distributed tropical species, found in Australia on 

 the coral reefs among sea- weeds. 



Genus G-omatokhynchtts, Haswell. 

 Carapace sub- triangular, rounded behind. Eostrum formed of 

 two triangular, pointed, slightly divergent cornua. Third joint 

 of external maxillipedes produced and rounded at its antero- 

 external angle. Carpus of anterior limbs carinate in the male. 



17. Gonatorhynchus tumidus. A.M. 



Gonatorhynchus tumidus, Haswell, Proc. Linn. Soc. N.S.W., 

 Vol. iv., p. 439, pi. xxv., fig. 4. 



Surface finely granulated, covered with hooked hairs which are 

 much closer on the rostrum and over the orbit ; gastric region 

 with a few irregular smooth tubercles ; hepatic regions prominent, 

 with a few small pointed tubercles ; anterior portion of the 

 cardiac region rounded, separated, together with the urogastric 

 region from the branchial by a broad, low, sinuous ridge, which 

 broadens out anteriorly to form a smooth pear-shaped elevation 

 on the inner part of the branchial region, and breaks up behind 

 into a number of small rugae ; branchial regions dilated, each 

 with two ovate, flattened tubercles situated close together towards 

 the centre, and three spinous tubercles towards the lateral margin. 

 Eostrum slightly deflexed. Upper orbital border ending behind 

 in a minute tooth, followed by two convergent spines separated 

 by open fissures. Basal joint of the external antennae about 

 twice as long as broad, concave from side to side, with a thin 

 outer lip, slightly notched in front, more prominent behind, 

 forming the lower rim of the orbit ; a small tooth at the antero- 

 internal angle. Arm (in the male) with a dorsal ridge ; propodos 

 slightly dilated, smooth ; fingers slender, pointed, mobile finger 

 with a large rounded tooth near its base, and a row of denticles 

 in its distal half ; immobile finger with the inner border concave 

 proximally, with a single small tooth near the base, straight 



