(506 CRUSTACEA. 



PEK/EUS gracilis. 



Gracillimus. Rostrum rectum, sat breve, oculis vix longius, supra 5-den- 

 tatum. Oculi longi, obconici. Antennarum internarum basis tenuis, 

 longissimus, carapacem longitudine cequans. Manus pedum sex anti- 

 corum carpo vix longior, apice parce pubescens ; digiti dimidii manus 

 longitudine. tegmentum caudate margine tri-spimdosum ; lamella 

 externa non articulata. 



Very slender. Beak straight, rather short, a little shorter than the 

 eyes, five dentate above. Eyes long, obconical. Base of first an- 

 tennae slender, very long, as long as carapax. Hand of six anterior 

 feet rather longer than carpus, and finger half as long as hand, a 

 few short hairs at tip ; three spinules on either margin of caudal 

 segment; outer caudal lamella not jointed. 



Plate 40, fig. 7 a, animal, enlarged ; b, caudal extremity. 



Sooloo Sea, twenty-five miles east of Panay. Collected, January, 

 27, 1842. Some sea-weed was seen floating by during the day. 



Length, eight to nine lines. Nearly colourless; a little reddish about 

 the mouth, and the bases of the thoracic and abdominal legs. Two of 

 the five rostral teeth are on the carapax, back of the base of the beak. 

 The eyes were directed straight forward in the specimen examined. 

 The antennae were mutilated, and the length of the flagella, therefore, 

 was not ascertained. Second and third joints of base of inner pair 

 together about as long as first joint, and third joint but little shorter 

 than second. 



Penult abdominal segment as long as two preceding, and having a 

 few minute spines on the back of it. Last segment ligulate ; apex 

 obtuse. Outer caudal lamella a little longer than inner. Six ante- 

 rior legs naked, except very short hairs on tips of hands ; third pair 

 about twice as long as first. The fifth pair was mutilated. 



