's RIJKS MUSEUM VAN NATUURLIJKE HISTORIE ~ LEIDEN. 183 



Ortmann's figure of M. laniger, it is impossible to find any difference, 

 except for the woolly hairy covering of the carapace in the latter case. 

 Laurie however has shown, that a hairy carapace is found in young 

 specimens and that it is „associated indifferently either with „flat, not 

 thorn-like" carapace-teeth *), or with acute, upturned carapace-teeth, or 

 with a somewhat intermediate form". 



De Man has already spoken of the probability that the M. Polleni of 

 Hoffmann is identical with M. latreillei; Ortmann and Laurie agree with 

 him. I cannot but confirm de Man's supposition; though Hoffmann has 

 made no mention of the fourth lateral tooth (including in the number of 

 teeth the external orbital angle) it is indeed present, as I could convince 

 myself in examining Hoffmann's specimen, still preserved in the Museum. 



There is no need to give new figures of this easily recognizable species, 

 as it is well figured by A. Milne-Edwards (1873) and by Miers; drawings 

 of young specimens are given by the latter author, by Ortmann (M. 

 laniger) and by Stimpson (1907). 



Finally Laurie gave photographic reproductions of four specimens; 

 we conclude from this series that the shape of the carapace may vary 

 considerably, in some cases being nearly equilateral, in other much more 

 elongated transversely. The whole surface is closely covered with large 

 granules and, in young specimens, with hairs, which gradually disappear 

 in older stages. On each branchial region there may be seen two longi- 

 tudinal rows of small granules. The grooves on the carapace are not very 

 conspicuous, only those circumscribing the mesogastric and cardiac area 

 being usually distinct; it is in these latter grooves, that slight traces of 

 the original hairy covering of the carapace may remain in adult specimens. 



The external orbital angle is large and directed obliquely forward or 

 straightly outward, dentated at the margins; the three following lateral 

 teeth gradually diminish in size distally. All the carapace-teeth may be 

 either spiniform or flat (Laurie) ; the first type seems to be the usual one in 

 young specimens. The upper orbital border is nearly straight and has 

 slightly any curve in adult specimens; in young specimens there may 

 be a more pronounced curve, though the orbital border does not project 

 farther forward than the external orbital angle. The front is very narrow, 

 occupying about one-tenth of the breadth of the carapace between the 

 external orbital angles. 



The male chelipeds are remarkably small ; they may attain a large 

 size only in the largest specimens known. The palm is granulated on 



1) Ortmann has given this character of the carapace-teeth as another feature to distinguish 

 his species from M. latreillei. 



