' ISOPODS OF NORTH AMERICA. 



293 



inent, indicating- partly coalesced segments. The terminal segment 

 has two tubercles situated on the convex dorsal surface, one on either 

 side of the median line, about the middle of the segment. This seg- 

 ment terminates posteriorly in three small teeth, one median and one 

 lateral to this on either side. The inner fixed branch of the uropoda 

 does not extend beyond the tip of the terminal abdominal segment. 

 The outer post-lateral angle is very acute. The outer branch of the 

 uropoda is very long- and extends beyond the inner branch a distance 

 equal to half the length of the inner branch. It terminates in a long 

 acute extremity. 



Only one specimen of this species was taken in Florida by Prof. 

 A. S. Packard. 



The type is in the Museum of Comparative Zoology at Harvard 

 College. Cat. No. 6732, M. C. Z. 



This species is named for Prof. W. S. Faxon, who very kindly 

 assisted me by letting me have for examination the collection in the 

 Museum of Comparative Zoology at Harvard University. 



EXOSPH/EROMA OCTONCUM (Richardson). 



Sphieroma octoncum RICHARDSON, Proc. U. S. Nat. Mus.,XXI, 1897, p. 836; Ann. 

 Mag. Nat. Hist. (7), IV, 1899, p. 180; American Naturalist, XXXIV, 1900, 

 p. 223. 



Locality. Montere}^ Bay, California. 



Body with all the thoracic segments, except the first, marked with 

 four conspicuous brown spots, two on either side of the median line, 

 and with two spots on the first abdominal segment, one 

 on either side of the median line. 



Head small. First pair of antennae reach almost to 

 the posterior margin of the first thoracic segment. Sec- 

 ond pair extend fully to the posterior margin of the first 

 segment. 



Thoracic segments subequal. Epimera broad and ex- 

 tending downward, forming an angle with the segments. 



First abdominal segment with 

 two low tubercles close together, 

 situated one on either side of the 

 median line; terminal segment 

 triangular, with apex narrowly 

 rounded and sides slightly infolded, forming a 

 small opening when seen from below. Six low 

 tubercles are situated on this segment, two in 

 longitudinal series on either side of the median 

 being a little farther apart than the upper 

 The uropoda do not reach 



& 



FIG. 309. Exos- 



PH^EROMA OC- 

 TONCUM. MAX- 

 ILLIPED. X51f. 



PlG. 310. EXOSPH^ROMA OC- 



TONCUM. ABDOMEN, x 13. 



line the lower ones 



ones and one on either side of the series. 



