's RIJKS MUSEUM VAN NATUURLIJKE HISTORIE — LEIDEN. 169 



rated and diminishing in size towards the distal end of the palm ; the 

 outer surface is not smooth, but the upper part is strongly tuberculated 

 and in the middle line, parallel with the margins, 5 — 6 larger tubercles 

 are arranged in a longitudinal row; between this and the strong ridge 

 near the under border the palm is nearly smooth ; the ridge is strongly 

 granulated on the palm, more so than in M. carinimanus, but simple on 

 the immobile finger. The fingers are bent downward, a character, already 

 observed by de Haan („digitis inferioribus sigmoïdeis") ; the immobile 

 finger has a rather small, very low tooth in the middle of its length; 

 according to de Man the dactylus has no larger tooth, but in reality 

 there does exist a very low one near the base. 



Comparing de Man's figures of the male cheliped of M. carinimanus 

 (Notes Leyden Museum, v. 12, 1890, pi. 4 f. 8) and that of M. dilatatus 

 (ibidem, pi. 4 f. 9) the differences between the two species are at once obvious. 



The Museum possesses eight specimens of the species under discus- 

 sion (four specimens preserved in alcohol), all males except one, from 

 Japan. This locality is the only sure record, for Doflein's specimen (a 

 young female) has by the author himself only with much reservation 

 been referred to M. dilatatus. 



Five of the Museum specimens present the following dimensions (the 

 first seems to have been measured by de Man, 1890, p. 79). 



12 3 4 5 



c? cT cT (ƒ cf 

 Distance between external orbital angle 26.5 25.5 25. — 24.75 20.75 

 Length of carapace 12.75 12.25 12.— 11.75 9.5 



M. brevis l ) (Herbst). (PL VI, Fig. 5). 



1804. Cancer brevis Herbst (nee Hilgendorf, de Man). Naturgesch. Krab- 

 ben u. Krebse, Bnd. 3 Heft 4. p. 9. pi. 60 f. 4 (East-India). 



1837. M. carinimanus H. Milne-Edwards, (nee Hilgendorf) Hist. nat. d. 

 Crust., t. 2 p. 65 (no record). 



1) Besides the synonyms here named yet two names should perhaps be included in the list, 

 though very little is known about the specimens referred to them. The first, M. laevimanas 

 (H. Milne-Edwards, Ann. Sc. nat. sér. 3, Zool., t. 18, 1852, p. 157) is only distinguished from 

 JU. carinimanus by the lack of the elevated ridge near the inferior border of the palm of the 

 male cheliped. The second, M. parvimanus (H. Milne-Edwards, Hist. nat. d. Crustacés, t. 2, 1837, 

 p. 65 and Ann. Sc. nat. sér. 3, Zool., 1. 18, 1852, p. 157) has very short and compressed chelipeds, 

 even in the male, and whereas the author in 1837 remarked that the ocular peduncles are much 

 elongated, this character is not mentioned in the Ann. Sc. nat., where the species is classed 

 among the species with short eye-stalks. Perhaps this species, as well as the „ Ocypode microcheles' , 

 of Bosc (Hist. uat. Crust, t. 1 p. 199, 1802) and the Macrophthalmus -parvimanus of Guérin 

 (Iconogr. Règne animal, Crust. pK 4 f. 1) have been founded on females of Vca (Gelast mus). 



