382 



BULLP:TIISr 54, UNITED STATES NATIONAL MUSEUM. 



The abdomen is composed of one segment with snture lines at the 

 base indicating another partly coalesced segment. It is rounded pos- 

 teriorly with the extremity truncate or slightly emarginate. 



The legs are more or less similar in .structure. 



SYNIDOTEA ANGULATA Benedict. 



Synidotea angnlata Benedict, Proc. Acad. Nat. Sci. Phila., 1897, pp. 395-396. — 

 RiCHARDwoN, Proc. U. S. Nat. Miis., XXI, 1899, p. 848; Ann. Mag. Nat. Hist. 

 (7), IV, 1899, p. 268; American Naturalist, XXXIV, 1900, p. 227. 



Localities. — Off Cape Johnson, Washington; off Destruction Island, 

 Washington; off Cape Flattery, Washington. 



Depth.— SI to 38 fathoms. 

 Body narrow, elongate, three times longer 

 than wide, 4 mm. : 12 mm. Length of abdo- 

 men one-third the length of the entire body, 

 4 mm. :12 mm. 



Head with a deep excavation between the 

 antero-lateral angles. Just posterior to the 

 frontal excavation is a I'idge produced into 

 two low tubercles, one on either side of the 

 median line. Eyes large and round, com- 

 posite, and placed about the middle of the 

 head near the lateral margins. The basal 

 article of the first antenna? is not expanded 

 and is about as long as the second article; 

 the third and fourth are sul)equal and each 

 is about one and a half times longer than the 

 second. The first pair of antemia? extend a little beyond the end of 

 the third article of the peduncle of the second pair of antenna?. The 

 basal article of the second antennae is short and almost inconspicuous 

 from a dorsal view; the second article is also short; 

 the third and fourth are about equal in length and 

 each is twice as long as the second; the fifth is nearly 

 twice as long as the preceding article. The flagellum 

 consists of twelve articles. When retracted the sec- 

 ond pair of antennse extend to the posterior margin 

 of the third thoracic segment. The maxilliped has a 

 palp of three articles. 



The second, third, and fourth segments of the thorax 

 are longer than the others. All the epimera of all the 

 segments are firmly united with the segments. The lat- 

 eral portions of the first four segments are expanded laterally with mar- 

 gins angulate. The last three segments have straight lateral luargins. 

 The abdomen is composed of one segment with latei'al sutures at the 

 ])ase, indicating another partly coalesced .segment. The posterior por- 

 tion is rounded, with apex slightly excavate. 

 The leo's are moi'c or less similai* in structure. 



Fig. 418. — Synidotea angui.ata 

 (After Benedict), x 4. 



Fig. 419.— Synidotea 

 angulata. maxil- 

 LIPED. X 27}. 



