156 DR BAIRD ON ENTOMOSTRACA. 



tion of body divided into five joints ; abdomen into about two ; 

 superior antennae long; inferior two branched; foot-jaws, three 

 pairs, large and well developed ; legs, five pairs ; eyes, two in 

 number. 



Genus 1st. — PoNTiA— if. Edwards, 



Head furnished with a moveable beak; foot-jaws well de- 

 veloped ; antennules two branched, serving the purpose of nata- 

 tory organs. Last pair of feet differ in construction from preced- 

 ing pairs. 



Sp. 1st. — Pontia Patersonii — Anomalocera Patersonii, Tern- 

 pleton* Trans. Ent. Soc. II. 



Genus 2d, — Cetochilus — Roussel de Vauzime, 



Head furnished with two small styliform prolongations. An- 

 tennules of two branches of nearly equal size. Third pair of foot- 

 jaws smaller than in preceding genus. Last pair of feet of the 

 same formation as the others. 



Sp. 1st. — Cetochilus septentrionalis, Goodsir. Edin. New 

 Philos. Jour. xxxv. Hab. Frith of Forth. 



Genus 3d. — Iren^us — Goodsir. 



Head furnished with a beak ; a large tubular organ arises from 

 the lower or abdominal surface of the body, in the superior extre- 

 mity of which the organs of vision are situated. The right an- 

 tennae are very much swollen a little behind the middle. 



Sp. 1st. — Irenseus splendidus, Goodsir. Edin. New Philos. 

 Jour. xxxv. Hab. Frith of Forth. 



As these last two species have recently been found by Mr 

 Goodsir in the Frith of Forth, I have little doubt they will be 

 found by future observers on the shores of Berwickshire also. 



P^CILOPODA. 



Order— SIPHONOSTOMA. 



Mouth furnished with a syplion, which possesses styliform man- 

 dibles. Thorax composed of several distinct rings, and having 

 three or four pairs of feet. Foot-jaws well developed. 



