Mr. C. Spence Bate on British Edriophthahnous Crustacea. 149 



the second gnatliopod. Posterior pleopoda single-branched, ter- 

 minating in hooks. Telson furnished with curved spines. 

 1. E. difformis. Thumb on the second gnathopod two-pointed. 

 Swansea, Plymouth, C S. B. 



Genus 7. Siphonocetus (Kroyer). 

 Lower antenna subpediform, longer than upper. First and 

 second gnathopoda prehensile. Posterior pleopoda single- 

 branched, terminating in hooks. Telson furnished with teeth or 

 hooks. Posterior pcreiopoda terminating in curved spines. 



1. *S^. Krbyeranus (mihi). Upper antenna short. Dactylos of 



the anterior pereiopoda styliform and without a curve. 

 Weymouth, Prof. Williamson. 



2. S. crassicornis. Basal joint of upper antenna having the ante- 



rior superior margin developed into a horn reaching to the 

 end of the second joint. 

 Northumberland, J. Alder, Esq. 



Subfamily III. COROPHUDES. 

 Construct abodes by burrowing in clay or mud, &c. 



Genus 8. Corophium (Latreille). 

 Lower antenna very large, much more powerful than upper, 

 pediform. Gnathopoda not prehensile. Posterior pleopoda short 

 and single-branched. 



1. C. longicorne. Lower antenna longer than the whole animal. 



Filament fused into a single articulation. A large tooth on 



the inferior surface of the penultimate joint of the peduncle. 



Moray Frith, Rev. G. Gordon. Glamorgan ; Devon, C. S. B. 



Medway, Dr. Leach, Coll. Brit. Mus. (White's Cat. Brit. Crust.) 



Family IV. Cheluridae. 



The three segments of the posterior pleon fused into a single 

 joint. 



Construct abodes by burrowing in wood, &c. 



Genus 1. Chelura (Philippi). 

 Upper antenna shorter than lower, furnished with a secondary 

 appendage. Lower antenna with segments of filament fused. 

 Telson single. 



I. C. terebrans (Philippi). Gnathopoda imperfectly cheliform. 

 Last segment of the anterior pleon produced into a large 

 spine dorsally and posteriorly. 



Dublin Bay, Thompson. Plymouth, C. S. B. Britain, Dr. Leach 

 [White's Cat. of the Brit. Crustacea). Ayrshire, Major Thomson. 



