D1NEMODRA. 85 



Genus 12. DINEMOURA Latreille, 1829. 



Syn. Dinematura Burmeister, 1833. 



Female. Carapace suborbicular, deeply excavated 

 posteriorly ; frontal plates narrow. The first free 

 segment of the thorax with small lateral lobes ; the 

 next segment narrow with or without rudimentary 

 dorsal plates ; the third segment with dorsal plates of 

 tolerable size, separated by a narrow median fissure, 

 and overlapping the anterior portion of the genital 

 segment. The genital segment of an oblong form 

 and with the postero-lateral corners produced into 

 short, broadly-rounded lobes. Abdomen small and 

 uniarticulate ; caudal rami tolerably large and 

 foliaceous. Between the genital segment and the 

 abdomen there is a very small joint with two dorsal 

 plates and furnished below with a pair of rudimentary 

 legs.* 



Antennas short and moderately stout, and armed 

 with strong hooked terminal claws. Mandibles long 

 and very slender, and provided with a few minute 

 teeth near the tip. Second maxillae slender, three- 

 jointed ; first maxillipeds also slender, and furnished, 

 each, with an apical claw and two small lateral pro- 

 cesses. Second maxillipeds moderately stout. Swim- 

 ming-legs all biramose ; first pair with both rami 

 two-jointed ; those of the second and third pairs 

 three-jointed, while in the fourth pair both rami con- 

 sist of tolerably large one-jointed foliaceous plates. 



Male. Carapace proportionally wider than in the 

 female. Second free thoracic segment without dorsal 

 plates. The dorsal plates of the third segment small 

 and overlapping only a small portion of the genital 

 segment. Genital segment cuneiform, wider towards 

 the distal end. Abdomen very narrow, biarticulate ; 

 caudal rami large. Swimming-legs biramose, both 



* C. B. Wilson appears to be the first to give an accurate description of this 

 part of the animal which he names the sixth segment. C/. ' North American 

 Parasitic Copepoda/ ' Proc. TJ. S. National Museum/ vol. xxxiii, pp. 374, 376 



(1907). 



