734 CRUSTACEA. 



the fourth and fifth joints ; they have at apex, like those of the Onis- 

 cinae, two or three very short joints, the last of which is slender and 

 somewhat spiniform, with short setules at the extremity. The legs 

 are all similar, or nearly so, and subequal, excepting that the seventh 

 pair is shorter and smaller, and unarmed with spinules. The last 

 thoracic segment is correspondingly much shorter than the preceding. 

 The mandibles have a denticulate apex, and plumose setae beneath. 

 The first pair of abdominal appendages in the male consists of a small 

 branchial plate, and a jointed pediform organ, consisting of five joints 

 and a small claw at apex. The other abdominal appendages to the 

 fifth inclusive are nearly circular lamellae. The stylets have a stout 

 but very short base, and two styliform branches. 



SCTPHAX ORNATUS. 



Coipus ellipticum, abdomine non ahrupto angustiore quam thorax. Caput 

 segmento proximo non brevius, transversim ellipticiim, oculis latera 

 capitis tegentibus. Segmenta thoracis subcequa. Abdomen 6-articulatum, 

 segmentk duobus anticis tliorace partim tectis, ultimum valde angustius, 

 ad basin latins. Styli caudales fere abdominis longitudine, basi per- 

 brevi, ramis paido inoequis, liirsutiusculis. Antennas dimidio corporis 

 paulo longiores. Antennae pedesque minute hirsuti. 



Body elliptic, abdomen not abruptly narrower than thorax. Head 

 not shorter than following segment, transversely elliptical, eyes 

 occupying the whole of the lateral margin. Segments of thorax 

 subequal. Abdomen six-jointed, two anterior segments partly con- 

 cealed by thorax, last segment very much narrower than preceding 

 and widest at base. Caudal stylets as long as abdomen, branches 

 little unequal, minutely hirsute. Antennae a little longer than 

 half the body. Antennae and feet minutely hirsute. 



Plate 48, fig. 5 a, animal, enlarged; b, b', antenna; e, c', mandible, 

 in different positions ; d, e, maxillae ; /, maxillipeds ; g, g', languette ; 

 h, h\ part of last pair of thoracic feet, from different specimens ; i, 

 second pair of abdominal appendages ; h, I, third and fourth pairs ; 

 m, fifth pair ; n, sixth pair or caudal stylets much enlarged ; o, part of 

 sixth pair of legs ; p, part of seventh. 



