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(California). Dana also includes ''Pinnotheres' chilensis H. Milne-Edwards i), but this has been 

 made by Heller the type of a new genus, Pinnaxodes, which is now generally considered at 

 most a subgenus of Pinnotheres. 



Pinnotheres -) Latreill^. 



1804. Pinnotheres Latreille. Hist. nat. Crust, et Ins., t. 6, p. j^. 



185 1. Pinnotliera Dana. Proc. Ac. Nat. Sc. Philadelphia, 1851, p. 253. 



1900. Pinnoteres Alcock. Journ. As. Soc. Bengal, v. 69, prt 2, p. 337. 



About the diagnosis of this well known genus, see Alcock and Miers'). 



The genus Pinnaxodes Heller*) is according to Burger") to be merged into the present 

 genus. Heller founded Pinnaxodes on the species P. hirtipes which subsequent authors 

 generally regarded as identical with P. chilensis H. Milne-Edwards (see note i), though 

 Miss Rathbun") is not quite certain about the matter, and at least maintains Heller's genus. 

 The only character by which Pitinaxodes is distinguished from Pinnotheres consists in the 

 dactylus of the external maxillipeds being placed end to end with the propodus and not 

 inserted far back on the inner side of the latter. Burger, however, stated that there are 

 gradual transitions between the two cases. 



The number of species of Pinnotheres is enormous and is certainly much larger than 

 that of all the other genera of the whole family taken together. The Indo-Pacific species, 

 excluding those of the West American coast, are more than 60 in number. As all these species 

 are small aud greatly alike, as in most instances only one of the sexes is known and the 

 carapace itself offers little remarkable, the discrimination within the genus is very difficult and 

 is founded on the shape of the external maxillipeds and on the relative length of the dactyli 

 of the walking leg's. 



Carcinology is much indebted to Burger, who in 1895 described about 30 new species 

 of Pinnotheres and at the same time united them all, together with .some others, known to 

 him by autopsy, into a synoptical key. In recent times Miss Rathbun^) examined a valuable 

 collection of Pi^tnotheres from the Gulf of Siam and again added 7 new species to the list. 



Little desirous as I am to increase the number of species, two or three cases have 

 induced me to do so in dealing with the "Siboga" collection. 



1) On the litercituie of this remarkable species, inhabiting the cloaca of Slrongylocenirotiis on the west coast of South America, 

 see S. J. Smith, Transact. Connecticut Ac, v. 2, 1870, p. 170. The (^ lives at the outside of the Echinid. 



2) About the controversy, raised by Alcock, whether in the word Pinnotheres and its derivations the h should be dropped 

 or not, the following must in my opinion not be lost sight of. Alcock quotes the authority of RuMPHius, who already in 1705 used the 

 orthography F'uinotercs. Now it is true that Aristotle speaks of T/vvonjpijc, but also the term TrivvcSt^pa^ is used by this author, and it 

 seems to me that the latter orthography is the right one, being derived from z-ivva and 0)fpxa (to hunt). It is not certain, which animal 

 is meant by Aristotle, for according to Latreille his text points to some small Sqiiilla or some Macrurous Decapod. Apart from such 

 arguments it seems preferable not to cling too firmly to Aristotle or even RUMPHIUS, but to return simply to authors using the regular 

 LiNNEAN nomenclature, and I see no reason to follow Al.coCK in his orthography. 



3) Rep. "Challenger", Brachyura, 1SS6, p. 275. 



4) Reise "Novara", Crust. 1865, p. 68, pi. 6, f. 2. 



5) Burger, Zool. Jahrb., Syst., Bd 8, 1895, p. 362. 



6) Proc. U. S. Nat. Mus., v. 21, 1899, P- ('°7i pl- 43i f- 'O — ■!• 



7) K. Dansk. Vid. Selsk. Skr., 7. Raekke, Afd. 5, n» 4, 1910, p. 330—336. 



99 



