136 PROCEEDINGS OF THE NATIONAI. MUSEUM vol. loi 



Diagnosis. — Ceplialon anteriorly with a very short triangulate me- 

 dian projection and an angiilate expansion at each anterolateral angle. 

 Eyes dorsal, separated from lateral border by a distance equal to the 

 width of one eye. Lobate lateral expansions of second and third 

 peraeon somites separated from one another by a distance exceeding 

 two times the length of anterior lobe. Pleotelson with spinelike, me- 

 dially recurved, posterolateral projections and a slightly trilobate pos- 

 terior margin whose medial lobe extends posteriorly beyond the 

 posterior extent of the posterolateral angles. Body and pleotelson 

 lateral areas setiferous. Male first pleopod structure not known. 



SUPPLEMENTARY DESCRIPTIVE NOTES 



Cephalon. — Wider than long, anteriorly with a small triangulate 

 median lobe, two wide mediolateral lobes and an angulate setiferous 

 projection at each anterolateral border. Eyes dorsal, bulging, located 

 a distance equal to the width of an eye from lateral border. 



Peraeon. — First somite with a trilobate lateral border, the medial 

 and perhaps the anterior lobes representing epimeral lobes. Lateral 

 borders of sixth and seventh somites with a small posteromedial lobe. 

 Epimera bilobed, anterior lobe the larger. 



Pleotelson. — Pleotelson with a medially recurved spinelike projec- 

 tion at each posterolateral angle; posterior margin trilobate, median 

 lobe exceeding the posterior extent of posterolateral angles. Lateral 

 borders setiferous. 



Maxilliped. — With three coupling hooks. 



Mandible. — Right mandible with incisor process having 5 teeth, 

 setal row with 15 setae, molar process with 10 setae along dentic- 

 ulate inferior margin and a large tooth; palp 3-jointed, second joint 

 as shown in figure 23, d. Left mandible differing from right in 

 having a 4-toothed lacina and nine setae in setal row. 



Peraeopods. — First peraeopod propodus with a row of 15 serrations 

 on inferior proximal margin; carpus expanded, with eighteen 2- 

 pointed setae along inferior margin. 



Uropods. — As long as pleotelson, inner branch slightly longer than 

 outer branch. 



Pleopods. — The male first pleopods have not as yet been described . 

 or figured. The specimens I have seen were females. 



Measurements. — Figured ovigerous female hypotype, length 5.4: 

 mm., width at widest part of second peraeon somite 2.1 mm. 



Type locality. — Puget Sound, Wash. 



Geographical distribution. — Pacific coast of North America, from 

 Turn Rock, Turn Island, San Juan County, Wash., to Laguna Beach, 

 Orange County, Calif. 



