Species of Maioid Crustacea. 25 



§ 2. Carapace usually produced over the bases of the ambulatory legs at its 

 postero-lateral angles, and with the postero-lateral margins nearly in a 

 straight line with the posterior margin. Anterior legs shorter, margins 

 dentate, but rarely spinose. (Partlieuopoides.) 



Lambrus (Parthenopoides) erosus. sp. n. 

 (PI. V. fig. 8.) 



Carapace triangular, slightly produced over the bases of 

 the ambulatory legs, its postero-lateral angles forming a decided 

 angle with the straight posterior margin ; its surface is without 

 tubercles or spines, but is uniformly and deeply pitted and 

 eroded ; somewhat larger pits mark the interspaces between the 

 gastric, cardiac, and branchial regions ; the rostrum is small, 

 triangular, and deflexed. The inferior surface of the carapace 

 is similarly but more regularly pitted. The anterior legs are 

 robust and eroded ; the arm greatly dilated ; the hand with a 

 prominent, oblique, scarcely dentated crest on its anterior 

 surface ; lower finger broad and triangular in shape. The 

 ambulatory legs are eroded and pitted like the body. Length 

 5 lines, breadth about 6 lines. 



Hah. Eastern Seas (H.M.S. ' Herald'). 



This species cannot be confounded with any other of the 

 genus known to me. 



Lambrus {Parthenopoides) expansus, sp. n. 

 (PL V. fig. 9.) 



Carapace subtriangular, and greatly produced at its postero- 

 lateral angles over the bases of the ambulatory legs ; the gas- 

 tric and cardiac regions are very prominent ; the surface of the 

 carapace behind and on either side of the gastric region is 

 very concave. There are three obscure rounded tubercles on 

 the gastric region, an obscurely granulated ridge on the 

 branchial regions, parallel to the antero-lateral margins, and 

 a few small granulations on each side nearer the cardiac 

 region. The straight posterior margin of the carapace and the 

 lateral margins, near the postero-lateral angles, are minutely 

 denticulated ; the lateral marginal series of denticles are 

 continued forward onto the pterygostomian regions. The 

 front is rather prominent, slightly concave above, granulated 

 neat and obtuse at its distal end. The anterior legs are 

 smooth and not eroded above ; arm with a series of closely- 

 set granulated teeth on its anterior margin; upper surface and 

 posterior margin obscurely granulated ; hand very robust, 

 with five or six teeth on its anterior margin; posterior margin 

 uneven, but not toothed ; fingers thick, smooth, and curved. 



