222 



Mr. Stimpson presented a description of a new crustacean 

 belonging to the genus Axius, of Leach, which genus had 

 not been before noticed as occurring on our coast. For a 

 perfect specimen he was indebted to Mr. S. Tufts, of Lynn, 

 by whom it was taken in twenty fathoms, off Scituate. 

 Fragments of the carapace, and the claws and legs, have 

 frequently been found by Mr. Stimpson in deep water, but 

 that of Mr. Tufts is the only perfect specimen yet disco- 

 vered. It more nearly resembles the lobster {Homarus 

 Americanus) than any of our known crustaceans, from 

 which, however, it is at once distinguished by its com- 

 pressed form and the non-articulation of the exterior caudal 

 plates. 



Axius SERRATUS St. Carapax smooth, with few scattered hairs, 

 much compressed, especially above posteriorly, where it is 

 almost acute ; transverse suture deep ; rostrum small, rather 

 elongated, with the medial carina sharp, and the lateral ones 

 serrated, with about seven teeth on each ; the carinas are con- 

 tinued, simple, less prominent, and diverging, for a little distance 

 on the carapax. Interior antennse nearly as long as the cara- 

 pax. Exterior ones with very long peduncles ; basal joint com- 

 pressed, concave, and slightly tortuous above, with a strong 

 spine, its movable scale very slender. External maxillipedes 

 very long and slender, with a small spine below near the end of 

 the third joint. Feet much compressed, and hairy on their 

 edges ; anterior pair with minute spines along the lower edges 

 of the second and third joints ; hand with very long hairs, cari- 

 nate above ; thumb strongly dentate on its inner margin ; finger 

 with shallow grooves, serrate within in the left hand, but not in 

 the larger right hand. The didactyle extremities of the second 

 pair of feet are very compressed, short, broad, and ovate. The 

 monodactyle extremities of the remaining pairs of feet are 

 thickly clothed with short hairs. Abdomen one and two-thirds 

 times the length of the carapax, rather broad, with the segments 

 terminating bluntly below ; caudal segment with a single minute 

 spine on each side of the medial furrow ; lateral caudal plates 

 each with a small spine at its insertion with the abdomen, the 

 interior ones sculptured with one, the exterior ones with two, 



