Mr. W. V. Guise on a new species of Alpheus. 51 



external face ; lower margin obtuse ; moveable finger much 

 shorter than the immoveable one. A spine upon the upper 

 margin of both arms at some distance from the termina- 

 tion/' 



It will be remarked that nothing is here said concerning the 

 character of the anterior portion of the carapace; but as this 

 species is said to be " tres voisine de la precedente " ("Alpheus 

 brevirostris" a new Holland species), which is characterized as 

 having the border of the supra-orbital hood rounded and without 

 spines, it is to be inferred that the like character also applies to 

 A. ruber. 



Alpheus Edwardsii. " Very closely allied to the preceding. Ante- 

 rior borders of supra-orbital vaults armed with a spine, so that 

 the front presents three nearly equal teeth. The second joint 

 of the superior antennae about half as long again as the first. 

 Lamellar appendage of the external antennae dilated a little 

 within towards the end, and not passing the footstalk of the 

 superior antennas. Pedipalps very narrow towards the end, 

 and extending beyond the footstalk of the superior antennae. 

 Anterior legs nearly of the same form as in the preceding 

 species, but more enlarged, and having the pincers more 

 irregular ; those on one side slender and lengthened/' 



Alpheus dentipes. " Closely allied to the preceding : having like- 

 wise the supra-orbital vaults prolonged into points, but 

 having the two anterior legs nearly of the same size; the 

 pincers of the smaller large at the base, but becoming ex- 

 tremely narrow towards the end; having the third articu- 

 lation of the second, third and fourth pairs of legs armed 

 with a pointed tooth externally, at one-third the length of 

 each." 



Upon comparison of my Channel Island individual with the 

 three species described above, I find the following points of 

 agreement and difference between them. 



It assimilates with A. ruber in having the larger hand fur- 

 nished with longitudinal carinse on the upper and the outer 

 surface ; 



Differs, in not having the moveable finger shorter than the 

 immoveable one ; and essentially in the spinous armature to the 

 supra-orbital hoods. 



It assimilates with A. Edwardsii in having the anterior edge 

 of the supra-orbital hoods armed with short spines ; and in 

 having the second joint of the superior antennae half as long 

 again as the first ; 



E 2 



