REPORT ON THE STOMATOPODA. 7 



adults with the larvae shows that the marginal spines of the telson present features which 

 are of the greatest significance, and as I shall make frequent reference to these structures 

 it will be convenient to give in this place a short description of them. The telson of a 

 Stomatopod is usually furnished with six marginal spines (see PI. I. fig. 3), which are 

 arranged in three pairs, and which I shall designate as the primary marginal spines. 

 The two nearest the middle line are the submedians ; the two nearest the anterior edge, 

 usually the farthest from the middle line, are the laterals ; and the one between the 

 lateral and the submedian on each side is the intermediate. Between these six 

 primary marginal spines there are others which are equally large and prominent 

 in the young larvae, but minute or absent in the adults ; these I call the secondary 

 marginal spines. 



Analytical Key, giving the moee prominent Diagnostic Characteristics 



OF EACH Genus. 



I. Sixth abdominal somite fused with telson ; rostrum with acute median and antero- 

 lateral spines. 



a. Dactyle of raptorial claw dilated at the base and unarmed ; hind body narrow 

 and thick ; marginal spines of telson crowded towards posterior edge. 

 Genus Protosquilla (PI. XVI.). 



II. Sixth abdominal somite distinct ; rostrum without antero-lateral spines. 



a. Hind body narrow and thick. 



1. Dactyle of raptorial claw dilated at base, and unarmed ; primary 



marginal spines of telson very large, with one or two secondary spines 

 on each side between the submedian and the intermediate. 

 Genus Gonodactylus (PI. XIV. fig. 1). 



2. Dactyle of raptorial claw not dilated at base, usually armed with 



marginal spines ; submedian spines of telson tijjped with movable 

 spinules ; from one to three secondary spines between the sub- 

 median and the intermediate. 



Genus Pseudosquilla. 



b. Hind body depressed and wide. 



1. Dactyle of raptorial claw dilated at the base and armed with marginal 

 spines. 



Genus Coronida. 



