40 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. XXVII. 



rior segments being- perfectly united with the segments and with no 

 trace of suture lines. 



The abdomen is composed of three segments, two short basal seg- 

 ments and one long, narrow terminal segment. 



The opercular val v^es consist of a single piece each, 

 the basal and terminal plates not being distinct or 

 separated by even a suture line. 



This genus differs from both Glyptonotus Eights 

 and Chiridotea Harger in having the lateral mar- 

 ofins of the head entire and not cleft; in having the 

 e^'es situated on these lateral ex})ansions of the 

 head; in having all the joints of the flagellum of 

 the second pair of antennae consolidated and form- 

 ing a single piece; in having the abdomen com- 

 posed of only three segments; in having the valves 

 of the operculum consisting of a single piece, and 

 in having a three- jointed palp to the maxillipeds. 



It differs also from Chrr/dotea Harger l)ut agrees 

 with Glyptonotus Eights in having the epimera dis- 

 tinct only on the last three segments of the thorax. 



SYMMIUS CAUDATUS, new species. 



Body elongate, broadest at second and third 

 thoracic segment. 



Head broader than long, with the anterior part 

 expanded laterally. The margins of these lateral 

 expansions are entire. The eyes are very small 

 and situated in the posterior angles of the lateral 

 lobes. There is no notch in the middle of the anterior margin, the 

 margin being very slightly produced in a widely rounded lobe. 



The first pair of antennae consist of four joints and are .somewhat 

 elongate. The last joint is long 

 and clavate. The second pair of 

 antenna? consist of six joints and do 

 not exceed in length the antenna^ 

 of the first pair. The joints of the 

 tiagellum are all consolidated into 

 a single piece, the terminal or flag- 

 ellar joint. 



The first four segments of the 

 thorax are about equal in length. 

 The fifth, sixth, and seventh seg- 

 ments become successively shorter, 

 and thoracic third segments, the sides converging beyond that point to 

 the narrow apex of the terminal abdominal segment. The epimera of 



Fig. 11.— Symmius cauda- 



Tl'S, NEW SPECIES. X 7. 



Fig. 12.— Symmius cavdatus; a, antenna of 



FIRST PAIE; b, ANTENNA OF SECOND PAIR. 



a X 10; & X 7. 



The bodv is broadest at the second 



