218 HALF AN HOUR WITH SHELL-FISH (BIVALVES). 



but this shell, as its specific name indicates, is short- 

 ened or truncated on one side. Its valves, also, are 

 more convex, and are covered with delicate grooves. 

 Of the Tellens (Tellinas) there are many species 

 common to our seas, all of which are very pretty, 

 abounding in the sandy muds. The largest of them is 

 the " Thick Tellen " (Tellina crassa, Fig. 118), which 

 Fi 118 is two inches in length, of a 



whitish colour, with pink or 

 red rays. The "Thin Tel- 

 len" (Tellina tennis) is about 

 the commonest of sea-side 

 objects, and one easily recog- 

 nisable by its flattened ap- 

 pearance, its polished surface, 



Tellina crassa. , ,1 in i j_'i n 



its thin shells, beautifully 



tinted inside and out with light rose colour, and, 

 externally, also, with bands of red. The Tellina 

 incarnafa is much larger than the above, and 

 narrower in proportion to its greater size. It is 

 confined generally to the southern coasts, where its 

 shape and colour soon introduce it to notice. The 

 latter is frequently orange, with streaks of pink and 

 white diversifying it. In the German Ocean, and 

 off the eastern coasts more particularly, is another 

 Tellen Tellina solidula, or Balthiea; It is remark- 

 able for being a very abundant fossil shell in our 

 boulder clay deposits (Fig. 119). It literally swarms 

 in the Baltic Sea (whence its name), and seems to de- 

 light in any sea-water that is rendered a trifle brackish 



