NO. 3618 GOXODACTYLUS — MANNING 3 



Gonodactylus dernani var. pruvotae Gravier, 1930, from New Cale- 

 donia, has been shown by Serene (1952) to be a synonym of Mes- 

 acturus spinosocarinatus (Fukuda, 1909). It need not be discussed 

 further here. 



This study indicates that the Indo-West Pacific species of Gono- 

 dactylus are not distributed necessarily throughout the area. Gono- 

 dactylus espinosus is apparently a Pacific species that does not occur 

 in the Indian Ocean; G. incipiens may also occur only in the Pacific 

 although it has been recorded in the Indian Ocean. Gonodactylus 

 hendersoni has a wider distribution pattern, between Hawaii and 

 Burma, but it has not been recorded from the western Indian Ocean. 

 Four of the species discussed herein, including G. demanii, G. spinosus 

 and two new species, are known to occur only in the western Indian 

 Ocean and Red Sea. 



Analysis of certain Indo-West Pacific species of Gonodactylus as 

 well as work on the American species leads me to believe that quali- 

 tative aspects of telson morphology are very important taxonomic 

 characters in this genus. The overall shape of the telson, the shape 

 and position of the marginal teeth and their carinae, the shape and 

 position of the dorsal carinae, and the presence and size of dorsal 

 spinules or tubercles are all important specific characters. It must 

 be kept in mind that the relative tumidity of the median and anterior 

 submedian carinae may change with age and may differ by sex. 

 Characters of the telson in combination with characters afforded by 

 the ocular scales, the rostral plate, the general shape of the lateral 

 processes of the thoracic somites, and especially in the demanii 

 section, the shape and setation of uropods, provide excellent char- 

 acterizations of the species now known. Color patterns and habitat 

 may also prove to be important. 



In the material examined, the number following the number of 

 specimens and sex is total length (TL), measured along the midline 

 from the apex of the rostral plate to the apices of the submedian 

 spines of the telson; all measurements are in millimeters (mm). All 

 specimens are in the U.S. National Museum. The illustrations were 

 prepared by my wife Lilly. The support of this study through the 

 Research Awards Program of the Smithsonian Institution is 

 gratefully acknowledged. 



In the following key I have included only the species reported 

 herein. Too little is known of the characteristics of G. affinis, G. 

 confinis, and G. segregates to include them. 



Key to Gonodactylus demanii and Allies 



1. Inner margin of uropodal endopod largely or completely devoid of setae, 

 margin smooth 2 



