266 



CRANGONIDJ3. 



man who caught them ' pug-shrimps ; ' he said he had 

 never observed them before this last winter. The females 

 were with spawn." 



Thus far Mr. Hailstone. Mr. Westwood's observations 

 follow : 



" Of Mr. Hailstone's Crustacea, probably the new Pon- 

 topJiilus will be regarded as possessing the highest interest, 

 inasmuch as the propriety of the establishment of the 

 group, which was at first confined to a single species, is 

 thereby proved. The character of this genus, as defined 

 by Dr. Leach, separating it from that of Crangon (of 

 which the common edible shrimp, Crangon vulgaris, is the 

 type), consisted in the very small size of the second pair of 

 legs, and the length and acuteness of the terminal joints of 

 the external foot-jaws or pedipalpi. These characters, 

 however, to which that of the spinous shell might be added, 

 have been deemed by the French crustaceologists insuffi- 

 cient to warrant the generic separation of the two groups ; 

 and, on considering the characters of the new species from 

 Hastings, the correctness of their opinion must, I think, be 

 admitted ; since it will be seen, that, in several respects, 

 its characters are quite intermediate between those of the 

 types of Crangon and PontopTiilus. Thus the shell, instead 

 of being armed with a double series of lateral and three 

 rows of dorsal spines, as in the latter, is 3-spinous only, 

 just as in the common shrimp ; while the terminal joint of 

 the foot-jaws is scarcely longer than the penultimate joint, 

 and is broad, flat, and obtuse. The central piece of the 

 tail is also much longer than in PontopMlus spinosus. Still 

 the minute size of the second pair of legs corresponds with 

 PontopMlus ; whence it will, perhaps, be more advisable 

 to divide the genus Crangon into two sections : first, those 

 with the second and third legs of equal length, the common 



