304 



BULLETIN 54, UNITED STATES NATIONAL MUSEUM. 



DYNAMENE DILATATA Richardson. 



Dynamene dilatata RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, pp. 832-833; 

 Ann. Mag. Nat. Hist. (7), IV, 1899, pp. 175-176; American Naturalist, 

 XXXIV, 1900, p. 223. 



Locality. Monterey Bay, California. 



Body oval; surface very granular; color yellow. 



Head rugose, with its anterior margin pro- 

 duced in a quadrangular process, having a small 

 median projection, sounded antero-lateral 

 angles and a thickened edge. First pair of an- 

 tennas extend to the posterior margin of the 

 head, first two joints flattened and enlarged; 

 first joint oblong, second joint triangular, and 

 half as long as preceding joint; third joint 

 small, as long as second, but half as wide; 

 flagellum six-jointed. Second pair of antennse 

 are but little longer than first pair and do not 

 reach the posterior margin of the first thoracic 

 segment. 



The thoracic segments are of equal length. 

 The epimera are square or oblong, with straight 

 lateral margins. 



The penultimate abdominal segment is short, 

 and crossed with suture lines. The terminal 

 segment is triangular with a small rounded 

 notch at the apex. There are three longitudinal ridges on the segment, 

 one in the median line, and one on either side of it. The uropoda are 

 short, not reaching the extremity of the abdomen, and regular^ 

 rounded. 



The legs are slender; the first two pairs are covered with long hairs 

 and extend in an anterior direction, the other five pairs extend in a 

 posterior direction. 



The type and only specimen was collected by Mr. Heath at Monterey 

 Bay, California, at the surface. Cat. No. 22568, U.S.N.M. 



DYNAMENE BENEDICTI Richardson. 



Dynamene benedicti RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 834; Ann. 

 Mag. Nat. Hist. (7), IV, 1899, p. 177; American Naturalist, XXXIV, 1900, 

 p. 224. 



Locality. Monterey Bay, California. 



Body oblong, oval; surface minutely granular; color dark gray. 

 Head with small median point. Eyes situated post-laterally. First 

 pair of antennas extend to the middle of the first thoracic segment; 



PIG. 327. DYNAMENE DILATATA. 

 a, HEAD AND FIRST THORACIC 



x 13i. 

 10|. 



