248 SOLENID^., 



moreover, three lateral laminae, two in the left valve, and 

 one in the right valve, whose length is hut trifling, and 

 whose extremities curve upwards and outwards. 



Although rarely attaining to such dimensions, the length 

 is occasionally as much as eight inches, and the breadth fully 

 one inch. It is decidedly the largest of the British Salens. 

 We have included in our synonymy the aS'. Ugula of Turton, 

 and the >S^. novacula of Montagu, having taken the former 

 froni the Tor Abbey sands, (the indicated locality,) and 

 ascertained with certainty that its dentition, (the sole 

 reason for its specific separation) is that of the perfect 

 siliqua before age has obscured the sharpness of its outlines. 

 The latter we have been enabled to determine, by an exami- 

 nation of the individual forwarded to Mr. Dillwyn by Col. 

 Montagu, in compliance with that gentleman's request for 

 information as to his species. The absence of lateral 

 laminse (the distinctive feature of the diagnosis) was in 

 all probability the result of accidental fracture, as they 

 are distinctly present in that typical specimen. 



The animal is elongated, thick, and of a yellowish-white 

 colour; its foot is very long and large, thick and white, 

 slightly angular and truncated at the extremity. The 

 base of the foot occupies about the middle of the shell, be- 

 tween which point and the siphons the mantle is closed. 

 At the point where it opens to let the foot pass, its margins 

 are minutely fringed. The posterior extremity is trun- 

 cated, the truncation being occupied by the very short 

 siphons, each with an orifice surrounded by a double fringe 

 of cirrhi. The margin of the mantles near the siphons is 

 slightly tinged with brown, as are also the siphons them- 

 selves. The labial palpi are larger and narrower than in 

 the next species. 



" This shell is common on most of our sandy shores. 



