SQUILLOIDEA. 629 



The anterior antennae are thrown forward, but only the terminal 

 setae are seen in a back view. Three cylindrical joints were observed, 

 the last longest and somewhat clavate, and terminating in several 

 longish hairs. The posterior antennae are cylindrical, three-jointed, 

 and terminate in a few hairs. Segments to which the eyes and an- 

 tennae belong, not distinctly separate. 



The animal frequently throws its abdomen forward along its venter 

 towards the head, and shows that the body is not attached to the 

 carapax, except near its head. 



ERICHTHUS SPINIGER. 



Carapax posticd latior, convexus, segmentum thoracis posticum non omnino 

 tegens ; angulis posticis longissimb productis et lat& divaricatis, infra 

 ad processus basin spinuld acutis ; margine postico rectiusculo, simpli- 

 cissimfi arcuato, ad medium spind crassd valde elongatd armato; mar- 

 gine laterali media inermi; angulis anticis spind breviter acutis; 

 rostra elongate, antennis anticis longiore. Segmenta abdominis 5 antica 

 subcequa, lateraliter et media dorsi spinuld armata; sextum dimidio 

 brecius, medium dorsi spinulis duc&us armatum ; ultimum paulo 

 transversum, postice laid truncatum et minute spinulosum, emargi- 

 natum, angulis productis acutis, lateribus tridentatw. Appendices 

 caudales longi, parte furcatd attenuatd, longiore quam cauda, furcis 

 valde inwquis. 



Carapax broader behind, convex, extending to middle of last segment 

 of thorax; posterior angles long produced, and widely divaricate, 

 and below base of process, a small spine or spinous process ; poste- 

 rior margin simply arcuate across, and bearing at middle a stout 

 and very long spine ; lateral margin without a medial spine ; an- 

 terior angles prominently acute ; beak long, longer than inner 

 antennae. Five anterior abdominal segments subequal, armed with 

 a small spinous process on either side, and another at middle of 

 back; sixth segment separate, half shorter than preceding and 

 having two spines on back ; last segment a little transverse, poste- 

 riorly wide truncate, minutely spinulous, emarginate at centre, and 

 angles acutely produced, on the sides three small teeth. Caudal 



158 



