122 DR. W. BAIRD ON NEW CRUSTACEANS. [Feb. 27, 



4. Description of Two New Species of Phyllopodous Crusta- 

 ceans. By W. Baird, M.D., F.L.S., Sec. 



(Plate XII.) 



1. Lepidurus angasii, sp. nov. (PI. XII. fig. 1.) 



Animal, including flap of tail-segment, about an inch long. Cara- 

 pace rounded, oval, of a pale horny colour (in spirits), covering more 

 than two-thirds of the abdomen. Central keel somewhat blunt or 

 obtuse for two-thirds of its length, becoming, near the extremity, 

 sharp and prominent. It is quite smooth and free from dentations. 

 Lunated notch at the extremity of the carapace rounded and finely 

 toothed on its margin. The edges of the carapace are smooth, ex- 

 cept for a very short distance at the posterior extremity, not dentated 

 or serrated, but of a rather thicker consistence, and of a darker 

 colour than the rest of the carapace. The dentations at the posterior 

 extremity are very small and blunt, requiring a good magnifying- 

 power to see them. The rings of the abdominal portion of body are 

 beset with a few stout spines, curved downwards. The flap of the 

 tail-segment has a fine keel running down its centre, with a few spines 

 on its anterior half; and its edges are distinctly, but very finely, 

 toothed or serrated. The filaments of the tail are rather more than 

 half the length of the body, and are densely clothed with numerous 

 very short fine setae. The appendages of the first pair of feet are 

 short, each articulation being shortly toothed on each side at the 

 upper portion. 



Hab. Rain-pools on the Gawler Plains, north of Adelaide, South 

 Australia (G. F. Any as, Esq. ; Mus. Brit.). 



Two specimens of this new animal were brought to this country 

 from South Australia by Mr. Angas. In 1850 I described, in the 

 'Zoological Proceedings' of that year, a species of Lepidurus (L. 

 viridis) from Van Diemen's Land, which approaches somewhat, in 

 general appearance, this species from South Australia. The L. vi- 

 ridis, however, is about double the size ; the carapace covers less of 

 the body, and the edges of the lower half of its length are serrated ; 

 while in L. angasii the carapace covers nearly two-thirds of the body, 

 and the edges are smooth and not serrated. The carapace, also, in 

 this species is more rounded in shape than in L. viridis, which is 

 decidedly more of an oval form. The colour of L. angasii is of a 

 pale horny hue ; whilst in L. viridis, as its name implies, it is of a 

 fine green. 



2. ESTHERIA NEWCOMBII, Sp. nOV. (PI. XII. fig. 2.) 



Carapace oval in shape. Beaks prominent, placed near anterior 

 extremity. The dorsal margin slopes directly down to the posterior 

 extremity, which is nearly as broad as anterior extremity. Ribs of 

 carapace about sixteen in number, narrower at the beaks, and be- 

 coming broader as they descend towards the ventral margin. The 

 intervals of the ribs are dotted with pnnctations, which are small 



