540 BULLETIN r)4, UNITED STATES NATIONAL MUSEUM. 



the first segment of the abdomen close to the anterior marg-in are two 

 large papillose processes, one on either side of the median line. 



There are five pairs of double-branched pleopoda, the branches in 

 the adult being similar and subequal, and both branches being in the 

 form of long, narrow lamella?, issuing from a common peduncle 

 attached to the lateral margins of the segments and forming a border 

 surrounding the abdomen. 



The uropoda are simple, in the form of two long, narrow, cylindrical 

 lamella? attached to the sixth abdominal segment. All seven pairs of 

 legs are present. 



The abdomen of the male is distinctly segmented. The first abdomi- 

 nal segment has two large rounded papilla? close to the anterior mar- 

 gin, one on either side of the median line. The sixth or terminal 

 segment is posteriorly produced at the apex in a long pointed process. 

 There are five pairs of single-branched pleopoda, in the form of long, 

 narrow sacs, attached one on each side close to the lateral margins of 

 the segments. The uropoda are a pair of small, simple processes, 

 attached one on either side of the terminal segment of the abdomen. 



All seven segments of the thorax are distinct. 



PHYLLODURUS ABDOMINALIS Stimpson. 



Phyllodurus ahdominaUs Stimpson, Bost. Jour. Nat. Hist., VI, 1857, pp. 511- 

 513.— LocKiNGTON, Proc. Cal. Acad. Sci., VII, 1877, Pt. 1, p. 57; Ann. Mao;. 

 Nat. Hist. (5), II, 1878, pp. 299-300.— Richardson, Proc. U. S. Nat. Mus., 

 XXI, 1899, p. 868; Ann. Mag. Nat. Hist. (7), IV, 1899, p. 337.— Bonnier, 

 Trav. de la Station Zool. de Winierenx, VIII, 1900, p. 250. — Richardson, 

 Proc. U. S. Nat. Mus., XXVII, 1904, p. 78. 



Localities. — Puget Sound on IJpogehix; Tomales Bay on ZTpogehla 

 p\uiettensi)i (Lockington); San Francisco Bay. 



Desc7'ipti<m of female. — Body ovate, a little longer than wide, a])0ut 

 one and a half times longer than wide, lo nun. : 14 nmi. 



Head a little wider than long, 3 mm.:4i nun., bilobate, with the 

 frontal margin produced in a rounded border. Eyes absent. The 

 first pair of antenna^ are small, usually inconspicuous from a dorsal 

 view, composed of three articles, the terminal article being minute, 

 the first article large and dilated. The second pair of antenna^ are 

 partly visible from a dorsal view. They are composed of five articles, 

 the terminal article being minute. 



I'he seven segments of the thorax are distinct. The anterior portion 

 of the lateral margins of the segments is occupied by the ovarian 

 bosses. Ijateral to the ovarian bosses on the first four segments are 

 the narrow epimeral plates. The posterior lobe of the lateral margin 

 is small on the first segment, becoming larger on the three following 

 segments. On the fifth segment the epimeral plate lies ])etween the 

 ovarian boss and th(> posterior lolx^ being lateral partly to both. On 



