408 PROCEEDTNGS OF THE ACADEMY OP [1879. 



Genus POLYONYX Stm. 

 Polyonyx macrocheles Stm. 



Porcellana macrodheles Gibbes, Proc. Am. Assoc, iii. p. 191. Ibid., 



Proc. Elliot Soc, i. p. 6, pi. i. f. 5. 

 Polyonyx macrocheles Stm., Proc. Phila. Acad., 1858, p. 229. Faxon, 

 B. M. C. Z., v. 256, pis. II. and III. (Development). 



In this species the males are smaller, with a narrower carapax 

 and with the chelipeds proportionately longer than in the female, 

 as will be seen by the following measurements : 



According to Prof. "Webster's labels, this species was found at 

 Beaufort, N. C, and Shark Shoal, N. C, in tubes of Chsetopterns, 

 as was noticed by Stimpson. Stimpson and Gibbes had speci- 

 mens from South Carolina. Newport, R. I. (Faxon). 



Genus EUCERAMUS Stm. 

 Euceramus prselongus Stm. Plate xiv. fig. 4. 



Euceramus prmlongus Stm., Am. Journ. Sci. and Arts, II. xxix. p. 445. 



Professor Webster obtained specimens of this curious crusta- 

 cean at Beaufort, N. C. (7 faths.), and Florida and Sarasota Bays, 

 Fla., from which the following description is drawn : 



Carapax nearly cylindrical, the sides but slightly arcuate ; sur- 

 face even, with minute transverse strife, which curve forward on 

 the sides. Front, between the eyes, about one-third the width of 

 carapax, three toothed, median tooth longer and projecting further 

 than the laterals. There is a slight excavation of the anterior 

 margin over the eyes and antennas. A minute acute spine at the 

 antero-lateral angle, and a little posterior to this is a slight emar- 

 gination of the lateral margin. Eyes minute, but little prominent. 



Antennal flagella about three-fourths the length of the carapax. 

 Feet stout ; chelipeds stout ; hands slightly roughened, fingers 

 about as long as the palm, not gaping; second pair shorter than 

 the third and fourth ; fifth pair small, and curved in the same 

 manner as in the other Porcellanidee. Terminal segment of ab- 



