124 jTirst annual tteuort 



sharp and short. Uropoda about hall' the length of the body, 11 

 mm. ; peduncle 3.5 mm., and about two-thirds as long as the outer 

 ramus; outer ramus slightly shorter than inner, which is armed with 

 a single spine. 



Alloniscus perconvexus Dana 

 (Figure <i!>) 



Locality Abundant in sand of upper beach under kelp ; very 

 abundant at high tides when driven out by the water. 



Color Dull gray mottled with black and white. 



Body ovate and convex, about twice as long as wide, 15 nun. by 

 7 mm. Head has frontal margin produced in the middle into a 

 rounded lobe; autero-lateral angles into an acute process extending 

 slightly beyond the eyes. Eyes composite and situated close to 

 lateral margins. First pair of antennas very small and rudimentary, 

 consisting of three small articles. Second antennae composed of five 

 articles and a flagelluni. First two articles short, third and fourth 

 longer and subequal, fifth over one and a half times as long as fourth. 

 Flagellum has three subequal articles. Second antennae thickly cov- 

 ered with small spines. Maxillipeds have a palp of three articles. 

 Palp of mandible wanting. 



First segment of thorax longer than the others, which are sub- 

 equal. On the first segment of the thorax a faint suture line extends 

 a short distance from the posterior margin and at an obtuse angle, 

 indicating the epimeron. On the next three segments sutures extend 

 the length of the segments. On the last three segments epimera are 

 not visible. Legs ambulatory, thickly spined. 



Abdomen consists of six segments, five subequal in length, the 

 sixth somewhat longer. First two are covered laterally by the last 

 thoracic segment. Last abdominal segment triangular and narrower 

 than all the preceding segments. Uropoda very short, about the 

 length of last abdominal segment; inner branch about half as long- 

 as outer. 



The whole surface of the body is covered with minute spines. 



Idothea rectilinea Lockington 



(Figure 70) 



Locality Abundant in pools, under rocks, on Phyllospadix and 

 among fucus at low tide. 



Color Male usually a light brown; female usually a very dark 

 brown with antenna? and legs of light brown. 



Body narrow and elongate; sides almost parellel and segments 

 very closely articulated ; five times longer than wide, 20 mm. by 4 

 mm. Dorsuni depressed longitudinally on either side of median line. 



