IÔ2 



Memoirs of the Indian Museum. 



[Vol,. IV, 



G. chiragra has been recorded by Heller (1863, p. 309), and others, from the Medi- 

 terranean ; but these records do not seem to be authentic. Steuer (1911, p. 734) has 

 re-examined specimens from Heller's collection found in the Adriatic, and has shown 

 that they are to be referred to Lanchester's G. chiragra var. mutatus, a form of 

 G. glabrous. This is the only record that can be accepted of the occurrence of the genus 

 Gonodactylus in the Mediterranean. 



var. platysoma, Wood-Mason. 



1895. Gonodactylus platysoma, Wood-Mason, Figs, and Desc. of nine Squillidae, p. n , pi. iii, figs. 3-9 

 {sine desc). 

 ? 1903. Gonodactylus chiragra var. acutus, Lanchester, Faun, and Geog. Maldives and Laccadives, I, 



p. 447, pi. xxiii, figs. 2, 3, 3a. 

 ? igio. Gonodactylus chiragra var. acutus, Lenz, in Voeltzkow's Reise in Ost-Afrika. II, p. 571. 



The specimens to which Wood-Mason gave the name of Gonodactylus platysoma 

 seem by their structure to possess better claims to varietal recognition than any of the 

 forms listed on p. 159. G. platysoma, as its name implies, is much more depressed 

 than G. chiragra and is proportionately broader. The greatest breadth of the abdomen 

 is from 21-5 to 23-5 % of the total length of the animal including the rostrum, whereas 

 it is always less than 20 % in typical G. chiragra. The difference does not appear great 

 when expressed in figures, but on actual comparison of specimens is a very conspicuous 

 feature (see text-fig., p. 161). 



The measurements of six specimens of var. platysoma are given below in con- 

 junction with similar measurements of eight G. chiragra, s.s. With respectto the figures 

 of the latter form it is to be noted that in normal specimens the percentage of length to 







3 





^ 









.g 



ö 











| g 





Locality. 



Sex. 





-û 



-2 







|3 



<8 *° 



■-P -S 







H c 



"ca<Ü 



aj 



a, u 







" H 



<u 



o,a 







H 



O 



ÇU 



G. chiragra var. platysoma. 





mm. 



mm. 



/o 



Andamans 



d 



80 



I7-5 



22 



Do. 



9 



79 



i8-5 



23-5 



Do. 



<$ 



77 



i6-5 



21-5 



Society Is. 



? 



75 



16-0 



21-5 



Mauritius 



9 



70 



15-5 



21-5 



Do. 



9 



48-5 



n-o 



22-5 



G. chiragra, s.s. 











Andamans 



c? 



100 



19-0 



19 



Do. 



d 1 



92 



17-0 



I9'5 



Do. 



9 



82 



15-0 



i8-5 



Do. 



9 



82 



15-5 



19 



Do. 



<S 



78 



15-0 



19 



Do. 



9 



72 



13-0 



19-5 



Coco Is. 



9 



71 



14-0 



i9-5 



Do. 



9 



57 



iro 



19-5 



