DECAPOD A . I' A LMMONIDM. 



UACROURA. 



GENUS PANDA LUS, LEACH. 



ASTACUS. Fabr. 



PAL^MON. Risso. 



PONTOPHILUS. Id. 



PANDALUS. Leach, Latr., Edw. 



Generic character. External antenna longer than the body, the 

 antennal scale unidentate on the outer margin. Internal antennae 

 with two filaments, the external one thicker; basal joint of the 

 peduncle hollowed above for the lodgment of the eyes. External 

 pedipalps slender, pediform. First pair of feet slender, shorter 

 than the others ; the terminal joint styliform, simple ; second pair 

 filiform, didactyle, unequal ; one much longer and more slender 

 than the other, both with the wrist and arm multiarticulate; third, 

 fourth, and fifth pairs of feet, slender, slightly diminishing in 

 length. Carapace armed with a long rostrum, the carina of which 

 extends half way to the posterior margin of the carapace, the 

 rostrum curved upwards, and denticulate above and below. Abdo- 

 men with the third joint gibbous, the upper and posterior margin 

 produced backwards. 



I HAVE always considered this genus as affording a dis- 

 tinct passage from the genus Hippolyte to Palcemon ; a view 

 of its relations, which has received an important confirmation 

 in the discovery of the H. pandalifonnis, which may be 

 considered as the osculant species on that side. Like 

 Hippolyte it has but two filaments to the internal antennae 

 and the carpus multi-articulate ; so that, in fact, it resem- 

 bles that genus in its essential characters even more nearly 

 than Palamon. 



