OF SOUTH DEVON. 285 



cation which will be highly acceptable to all naturalists in 

 this quarter. 



In the following paper I have followed Cuvier's ■ Regne 

 Animal,' in which the Crustacea were arranged by Latreille. 



The class Crustacea in the ' Regne Animal * has two sec- 

 tions, viz., Malacostraca and Entomostraca. 



The Malacostraca are composed of five Orders, viz., De- 

 capoda, Stomapoda, Amphipoda, Lcemodipoda, and Isopoda. 



MALACOSTRACA with pediculated moveable eyes. 



Order I. — Crustacea Decapoda. These have the head close- 

 ly united to the thorax, both of which are inclosed in one 

 entire shell or carapace, divided by lines into different re- 

 gions, which indicate the places occupied by the principal 

 interior organs ; they have a vascular and nervous system ; 

 the lateral borders of the carapace fold down to protect the 

 branchicBy leaving an opening anteriorly for the passage of 

 the water; the six jaw-feet are all of different forms, ap- 

 plied to the mouth, divided into two branches, the exterior 

 of which is like a small antenna ; the two anterior, and 

 sometimes the four following feet are talon- shaped, the 

 last articulation but one is dilated, compressed, and in the 

 form of a hand. 



Family 1. Decapoda brachyura, or short- tailed Decapods. 



Genus CANCER. 



Section 1. Pinnipedes or swimmers have the last feet with a 

 flattened or fin- shaped articulation. 



Polybius, sub-genus. 



P. Henslowii. A tine specimen was obtained from the pilchard-nets at 

 Bantham, in deep water, by Mr. C. Prideaux, and is now in the col- 

 lection of the Plymouth Institution. 

 Portunus, sub-genus. 



P. puber, Harbour or Mary Crab. Common on our coast ; three speci- 

 mens are in the Museum of the Plymouth Institution. 



P. mcenas, (Carcinus, Leach), Common shore Crab. Abundant. 



P. corrugatus. Dr. Leach says ('Linn. Trans.' vol. xi.) "habitat in Bri- 

 tannia rarissime ;" and afterwards states that the young was obtained 

 in Plymouth Sound by Mr. C. Prideaux, who informs me that he pro- 

 cured it by the trawl net. My friend Mr. Couch, of Polperro, also 

 states that he has obtained one specimen in his neighbourhood, so that 

 it may be considered as belonging to our coast, although but rarely 

 found from its habit of frequenting the deep sea. 



P. marmoreus. Frequently obtained at Torcross by Montagu ; Edinb. 

 Eucycl. vol. vii. p. 391. We have four good specimens in our Muse- 

 um, presented by Mr. C. Prideaux. 



P. depurator, the Flying Crab of fishermen. Not uncommon : we have 

 two specimens, obtained by the trawl, from Mr. C. Prideaux. 



