Mr. C. Spence Bate on British Edriophthalmous Crustacea. 139 



4. A. Ampulla (Kroyer). Lower antenna live times as long as 



upper. 



Moray I'rith, Rev. G. Gordon. Banff, Mr. Edwards. 



5. A. denticulatus. Posterior and inferior extremity of the second 



and third segments of the anterior pleon produced into a 

 tooth-like process. 

 Moray Frith, Rev. G. Gordon. Banff, Mr. Edwards. 



Subfamily III. TETROMATIDES. 



Eyes four : not compound. Upper antenna in advance of the 

 lower. 



Genus 6. Tetromatus* (mihi). 



Head projecting forwards as a snout. Upper antenna pro- 

 ceeding from the extremity; lower situated far posteriorly. 

 Mandible palpigerous. Gnathopoda but imperfectly prehensile. 



1. T. trjpicus. Head and anterior segments much compressed. 



Upper antenna half as long as the lower, the lower as long as 

 the animal. Posterior margin of the last segment of the 

 anterior pleon not ornate. 



Moray Frith, Rev. G. Gordon. Plymouth, F. P. Smyth, Esq., 

 C. S. B. 



2. T. Bellianus. Upper antenna not so long as the peduncle of 



the lower. Posterior edge of the last segment of the an- 

 terior pleon ornate. 



Moray Frith, Rev. G. Gordon. Plymouth Sound, C. S. B. 



Subfamily IV. PONTOPOREIDES. 

 The shell of the head developed anteriorly beyond the head so 

 as to look like a hood. Upper antenna situated in advance of 

 the lower. 



Genus 7. Westwoodia (mihi). 

 Shell of the head produced to a point. Upper antenna not 

 appendiculated. Telson entire. 



1. W. ceecula (mihi). Eyes converging into a single organ, 

 situated above and in advance of the superior antenna. 

 Head not produced into a rostrum. First gnathopod sub- 

 prehensile ; second gnathopod simple, fringed on the an- 

 terior margin of the propodos with a brush of hair. 

 Moray Frith, Rev. G. Gordon. Plymouth, from trawlers, C. S. B. 



* It is not improbable that it will be necessary to yield this genus to that 

 of Pseudophthalmus of Stympsou (Nat. Hist, of Grand Manan, which work 

 the author has only seen since this paper has been in type); the only 

 doubt resting on the form of the third and fourth pairs of legs. In the 

 American genus they are " elongated, tapering, with the second joint very 

 small, the third expanded to a hand." In Tetromatus they are slight and 

 tapering, with the terminal joint exceedingly long and styliform. 



