ON STRIDULATION 

 IN CRUSTACEA DECAPODA 



I. Introductory Remarks. 



It is a well-known fact that stridulating organs exist in a 

 number of species belonging to genera of very different families 

 of Crustacea Decapoda; most of our knowledge on this topic 

 down to the year 1899 has been put together by Ortmann in 

 Bronn: Klassen und Ordnungen des Thierreichs, Bd. V, II. 

 Abth., Crust. 2, p. 1245. Structural features interpreted as 

 stridulating organs have been discovered in three species of 

 PencBOpsis (de Man, 191 1) of the family Penseidae; in several 

 species of some genera of the Palinuridse (Ortmann, 1. c.) ; in 

 Thalassina anomala Herbst (Pearse, 191 1) of the family Thalas- 

 sinida?; in Coenobita ritgosa H. M.-Edw. (Hilgendorf, 1869) of 

 the family Coenobitidse ; in Clibanarius strigimanus White (Hen- 

 derson, 1888) of the family Paguridse, and in a number of crabs. 

 Among the tribe Oxj'stomata such organs are known only in 

 the species of the genus Matida (Hilgendorf, 1869; Ortmann, 

 I.e.); in the tribe Oxyrrhyncha they are unknown ; in the old 

 tribe Cyclometopa they exist in Pscudozius Edwardsii Barr. 

 (Barrois, 1888) of the family Xanthidae, in Ovalipes bipustulatus 

 H. M.-Edw. (Wood-Mason, 1878) of the family Portunidse, and 

 in a few African species of the genus Potamon (Caiman, 1908) 

 of the family Potamonidse. In the tribe Catometopa organs are 

 found in all species excepting one of the genus Ocypoda (various 

 authors), in some species of MacrophtJmlmiis, in Helice and 

 Metaplax (Hilgendorf, de Man, Ortmann), all l)elonging to the 



