616 CRUSTACEA. 



Digitus chelae maximae non armatus. Pars cephalothoracis antica os precedens 

 parte subsequente brevior. Carapax thoracem saepius omnino tegens. 

 G. 3. ALIMA, Leach. Appendices branchiales obsoleti. Digitus chelae maximae 

 non armatus. Pars cephalothoracis antica os precedens parte sequente longior. 

 Carapax thoracem saepius omnino non tegens. 



FAMILY!. SQUILLID^E. 

 GENUS LYSIOSQUILLA, Dana. 



THIS division of the old genus Squilla is quite distinct in its habit 

 from the rest of the group. In the species allied to S. mantis (our 

 genus Squilla), the carapax is subovate, narrowing much anteriorly, 

 with acute anterior angles, and the abdomen has its sides through the 

 posterior two-thirds nearly or quite parallel, with the segments all 

 more or less costate. But in this group, besides the very lax articu- 

 lation of the body, the carapax is broad and short, hardly narrower 

 anteriorly, with the angles rounded before and behind, and the abdo- 

 men widens gradually from its base, besides having the surface of the 

 four or five anterior segments smooth. The antennary segment is 

 but partly covered by the scale above, and in this respect the species 

 are like the mantis section, and unlike the third section or Pseudo- 

 squillce. 



The Squilla maculata, /S. vittata, and S. scabricanda (Edwards, Crust., 

 ii. 518, 519) belong to this genus. 



LYSIOSQUILLA INORNATA. 



Carapax vix dblongus, lateribus arcuatis. Segmentum antennale late 

 obovatum, acutwn. Oculi grandes, basi extus unidentato. Abdomen 

 longum, segmentis antepenultimo ad marginem posticum penultimoque 

 ad margines anticum et posticum breviter spinulosis, segmento caudali 

 paulo transverse, medio dorsi longitudinaliter gibboso, margine postico 

 semicirculari, dentato, dentibus numerosis (plus viginti) et valde in- 

 cequis, margine laterali recto, minute denticulato. Digitus chelae 

 maximce 9-LQ-spini-dentatus. Appendwum caudalium rami duo ferme 

 cnguales. 



