281 ETENIXGS AT THE MICEOSCOPE. 



are jointed independentlv, on rounded shelly knobs, 

 and are doubtless moved by strong muscles. Under 

 pressure, the knobs and the fins are brought out with 

 beautiful distinctness. Here a2;ain we have true 



CD 



jointed limbs. 



On the front vou may discern a pair of tiny an- 

 tennse, each bearing a pencil of very fine bristles. 

 And just beloM' the level of their base, in the centre of 

 the dorsal region, you see the large eye, of a deep red 

 hue, so deep that it frequently looks as if it were ac- 

 tually and intensely black. Just below the eye appa- 

 rently, but considerably more towards the ventral as- 

 pect, there is a huge mastax, occupying almost half the 

 length of the whole body. The jaws are very simple 

 in their constiniction, and therefore very instructive, 

 for thev contain the same elements as in Brachioniis : 



•J 7 



but from their excessive tenuity, and for other reasons 

 connected with the form of the animal, they are calcu- 

 lated to tax to the utmost your perseverance and skill 

 in manipulation to resolve them. Tliey were an em'g- 

 ma to me for vears. 



The great mastax is pear-shaped, pointing obliquely 

 towards the middle of the belly. This form is owino: 

 to the great length of the fulcrum^ and the wide cur- 

 vature of the mallei. Tlie rami are very broad, some- 

 what square at their base, flat, but much arched longi- 

 tudinally. They open and shut vigorously, with a 

 snapping action, but are not protruded from the front ; 

 their whole interior edijes come into contact. The 

 mallei are simple slender bent rods, apparently without 

 distinct articulation. During life they are thick and 

 irregular in outline, owing to their being invested with 

 dense muscles ; as is the whole upper portion of the 



