22 • SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL.98 



Tclcophrys cristtdipes Stimpson 2$ (1 ovig., 1 juv.) 



Pachygrapsus minutus Milne-Edwards i$ ovig., 20 juv. 



In the figure given by Milne-Edwards for P. minutus (Nouv. 

 Arch. Mus., Paris, vol. 18, p. 292, pi. 14, fig. 2, 1873) the posterior 

 border of the merus of the last pair of legs is without armature 

 except at the postero-distal angle. 



The merus of the last pair of legs of P. murrayi, as Caiman states 

 ( Proc. Zool. Soc. London, 1909, p. 708, pi. 72, figs. 4, 5, 1909), "has 

 two smaller teeth [besides those at the postero-distal angle] side by 

 side near the proximal end." One could perhaps better describe these 

 two small, yet somewhat elongated, juxtaposed teeth as a bidentate, 

 tuberculiform tooth. From between the two denticles of this bidentate 

 tooth a stiff hair or seta arises ; proximal to this tooth are two or three 

 little denticles on the inner, ventral margin of the joint. The upper 

 margins of the ambulatory legs are furbished with a close-set fringe 

 of "feathered" setae, thickest on the propodi of the last pair of legs, 

 and probably present on all joints. The hairs of this fringe are easily 

 broken off, at least in preserved material, as they are more or less 

 wanting on certain legs and joints. Such a fringe is not mentioned 

 by Dr. Caiman nor shown in his figure of the type. The front of 

 our specimens is about, or a little more than, half the width of the 

 carapace ; otherwise Caiman's description of murrayi fits them almost 

 exactly. 



Because of this apparent difference I was inclined to believe Cai- 

 man's species other than the one briefly described by Milne,-Edwards. 

 However, the view of a number of authors that the former is 

 identical with the latter is fully substantiated in a communication 

 which I recently received from Prof. L. Fage, of the Museum 

 National d'Histoire Naturelle, Paris, to whom I am more than 

 grateful : 



Je viens d'examiner les cinq echantillons de Pachygrapsus minutus qui ont 

 servi a la description de Milne-Edwards. lis possedent la petite epine geminee 

 au bord posterieur du meros de la derniere paire de pattes. 



J'ai compare ces echantillons avec la fig. du Sesarma murrayi et je n'ai trouve 

 aucune difference. 



La synonymie n'est pas douteuse. 



Percnon abbreviatum (Dana) 2 juv. (c?$) 



A first eastern Pacific record for the species, originally described 

 from Tahiti and taken since that time in the Indian Ocean, and at 

 Hawaii, Fanning, Ocean, and Wake Islands. 



In the absence of an available key to the valid species of Percnon, 

 the following tentative one is offered. 



