42 l>li. W. T. CALMAN ON A COLLECTION OF 



Lambhus (Pakthenolambkus) confragosus, n. sp. (Plate 3. figs. 27 & 28.) 



Bescriptioii of female. Carapace roughly triangular in outline, about as long as broad. 

 Rostrum truncated and considerably deflexed. Hepatic regions projecting in tbe form 

 of a vertically compressed, narrow, bluntly pointed tooth. In front this tooth is defined 

 by a deep notch separating it from the postorbital angle, and behind a shallower excava- 

 tion marks it off from the convex, crenated, lateral margin. Tlie postero-lateral corners 

 are produced into short, blunt spines. The posterior margin is irregularly toothed, with 

 a marked excavation on either side a little way from the outer end and an obtuse median 

 angle, which projects well beyond the line joining the postero-lateral corners. The 

 surface of the carapace is very uneven and irregularly granulated and pitted. The 

 gastric and cardiac regions rise each into a short, blunt spine, and a smaller spine or 

 large tubercle lies between the cardiac spine and the posterior margin. The branchial 

 regions are inflated, topped with oblique crests of granules, and separated from the 

 median regions of the carapace by well-marked grooves, which sink into deep fossae on 

 either side of the gastric and cardiac regions. 



The chelipeds are very heavy, slightly unequal, and aliout one and a half times the 

 length of the carapace. The merus is irregularly toothed along its anterior and posterior 

 borders. The hand bears on its outer (or upper) margin two thin, rounded, cristiform 

 lobes, of which the larger is close to the proximal end. The upper surface carries an 

 oblique and irregularly toothed crest, and is elsewhere unevenly granulated. The fingers 

 are rather less than half the length of the palm, and the dactylus is toothed and granulated 

 on its outer (or upper) margin near the base. The ambulatory legs are much compressed, 

 with the upper and lower margins of the joints serrate. 



Length of carapace 15 mm. 



A second specimen, only 8 mm. long, probably belongs to the same species. The 

 carapace is a little longer than broad, the rostrum is tridentate and even more strongly 

 deflexed than in the specimen above described. The hepatic prominences, though very 

 well-marked, are not so much compressed and dentiform. The surface of the carapace 

 is smoother, and the crenatious of the lateral margins less numerous. The chelipeds 

 are rather more slender, and there is only one cristiform lobe on the outer edge near 



the base. 



The species described above, Avhich I suppose to be ncAV, resembles in general form the 

 L. tarpeius of Adams and White, but differs from it in the much more rugged surface of 

 the carapace, in the compressed dentiform shape of the hepatic prominences, and in the 

 armature of the chelipeds, which in the last-named species lack the flattened cristiform 

 lobes on the outer margin of the hand. Many species, however, of this extensive genus 

 are known to vary within wide limits, and it is possible that a larger series of specimens 

 than has been accessible to me would unite the present form with one or other of the 

 species already described. 



LocuUUj. " Chanuel between reefs, Mer." 



