112 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.57. 



SYNIDOTEA EPIMERATA, new species. 



Fig. 33. — Synidotea 

 epimerata. x 3 j. 



Body oblong-ovate, a little more than twice as long as wide (6 mm. ; 

 13 mm.). 



Head with the front excavate, the antero-lateral angles being very 

 acutely produced. In the middle of the frontal excavation is another 

 small excavation. The eyes are large, composite, 

 and situated close to the lateral margin, about 

 half way between the anterior and the posterior 

 margins. In front of each eye, close to the anterior 

 margin, is a prominent tubercle. Just posterior to 

 the median excavation of the anterior margin is a 

 single prominent median tubercle. A series of 

 small tubercles in a transverse row lies just back 

 of the median tubercle. The transverse ridge at 

 the posterior extremity of the head has a single 

 median tubercle. The first pair of antennae have 

 the first two articles about equal in length; the 

 two following are also about equal in length and 

 each is a little longer than either of the preceding 

 articles. The first antennae extend to the middle 

 of the fourth article of the second pair of antennae. 

 The first two articles of the second antennae are short and subequal 

 in length ; the third and fourth articles are also subequal, and each 

 is twice as long as either of the preceding articles; the fifth article 

 is about one and a half times as long as the fourth; the flagellum 

 consists of twelve articles. The second antennae, when retracted, 

 extend to the posterior margin of the third tho- 

 racic segment. 



The first thoracic segment is shorter and nar- 

 rower than the three following segments and has 

 the lateral margins angulate. There are distinct 

 epimera on the anterior part of this segment which 

 are not present on any of the following segments. 

 The epimera arise from the underside of the lateral 

 margin and project anteriorly beyond the place 

 where they are visible in a dorsal view. The lateral 

 margins of the second segment are also angulate ; 

 those of the following segments are straight. The 

 last three segments gradually decrease a little in 

 length. The second, third, and fourth segments are about equal in 

 length. On each one of the segments is a small median tubercle sit- 

 uated close to the posterior margin. 



The abdomen is composed of a single segment with a suture line 

 distinct at the sides, but less distinct in the middle, indicating another 



Fig. 34. — Synidotea 

 epimerata. max- 

 ileiped. X 23. 



