170 CRUSTACEA. STOMAFODA. 



ORDER II. STOMAPODA. 



Branchiae in the form of tufts or plumes suspended on the infe- 

 rior appendages of the post-abdomen; head large, distinct from 

 the trunk, and in two parts ; shell membranaceous ; interme- 

 diate antennae terminated by two or three filaments ; six poste- 

 rior feet filiform ; a foliaceous fin at the extremity of the body. 



FAMILY I. UNIPELTATA. 



Body narrow and elongated ; thorax with an anterior elonga- 

 tion bearing the intermediate antennae and eyes ; exterior feet- 

 jaws and the four anterior .feet terminated in a monodactyle 

 hand or forceps, of which the moveable finger or hook is form- 

 ed by the tarsus ; the other six feet are proper for swimming, 

 with the last joint in the form of a brush ; lateral antennae 

 with a scale at the base, and the intermediate ones terminated 

 by three filaments. 



Gen. 1. SQUILLA, Fab. Lat. Cancer, Lin. 

 Four triarticulated antennae, the two intermediate longest, ter- 

 minated by bristles ; two external ones single, with a folia- 

 ceous scale at their base ; thorax posterior, divided into three 

 narrow and pedigerous segments ; tail large, of six segments, 

 the last with fan-shaped appendages. 



The Squillse are remarkable for their singular conformation, and the situation of 

 their branchiae. The last two feet-jaws form two large projecting arms, each termi- 

 nated by a moveable claw, dentated or pectinated on its internal side, which gives the 

 animal the aspect of insects of the genus Mantis. The anterior part of the thorax is 

 much behind on the body, and it appears as if the segments which supported the feet 

 did not belong to the thorax. The tail is large, long, and composed of six segments, 

 of which the last is furnished with fan-shaped appendages. 



S. mantis, Fab. Moveable toe of the forceps with six spines with- 

 in, which enter into as many cavities in the opposite margin ; body 

 and abdomen with six longitudinal carinae above ; colour silvery 

 white, shaded with blue and violet ; eyes golden green ; feet sea 

 green ; two violet blue spots on the last segment of the abdomen. 

 Inhabits Mediterranean sea Herbst, pi. 33, fig. 1. 



S. maculata, Fab. Very large ; body smooth above ; moveable claw 

 of the forceps much bent at the end and pectinated ; last seg- 

 ment of the abdomen rounded, with three dentations on the pos- 

 terior and lateral angles. Indian seas. Rumph. Mus. pi. 3. fig. E. 



Gen. . ERICHTHUS, Lat. Squilla, Fab. 

 Antennae, mouth, and eyes as in the preceding genus; shell broad, 

 prolonged behind to the posterior extremity of the trunk ; tail 

 composed of eight pretty broad segments, and bending down- 

 wards and forwards, so as to cover the animal below ; five 

 pairs of swimming feet under the tail ; a foliaceous appendage 

 at the origin of the feet which surround the mouth. 



