118 A. D. MICHAEL ON TWO SPECIES OF ACAEINA. 



epimera of the first pair of legs, which are short and broad. Be- 

 hind the second pair of legs a third ridge leaves the sternal one, and 

 extends to the edge of the body, where it joins the epimera of the 

 second pair of legs which send broad bands beneath the skin, sup- 

 porting the coxje of these legs and joining the epimera of the first 

 pair. A fourth ridge starts from the sternal ridge opposite the 

 cox£e of the third pair of legs, and inclines slightly backwards, but 

 only runs about half way across the abdomen. A fifth ridge runs 

 along the posterior margin of the cephalothorax, and it bears in the 

 centre a triangular plate. Each epimeron of the third pair is a 

 small, almost square, piece at the anterior margin of the coxae ; a 

 little outside the centre it sends a strong shaft outward and slightly 

 backward, where it joins at somewhat less than a right angle to a 

 long chitinous bar, which runs forward along the side of the 

 cephalothorax until it nearly reaches the coxse of the second pair, 

 where it turns round and soon splits into several short, fine, radiat- 

 ing spines or blades. The epimera of the fourth pair are short bars 

 between the coxte of the third and fourth pairs, and send a thin, 

 transparent, curved blade right across the third pair of cox^e. The 

 stigmata are most singular, consisting of short, flexible, bell-shaped 

 projections immediately behind the first pair of legs ; they are set 

 on a tubular peduncle, which communicates with a sub-cylindrical 

 air sac or peritreme, which lies along the lateral margin of the body; 

 from this two bunches of trachese start, one near the middle, and 

 one at the posterior extremity ; they are distributed to all parts of 

 the body. Five principal bands of muscle may be clearly seen 

 inserted in each coxa of the first two pairs ; they arise from the 

 sternal and lateral ridges before mentioned, each set of five embrac- 

 ing an angle of the sternal and lateral ridges, and proceeding 

 obliquely forward to the coxa, becoming closer together as they ad- 

 vance : the muscles inserted into the third coxse run almost straight 

 across from the sternal ridge, those of the fourth pair run obliquely 

 backwards from the sternal and short ridges. 



The excretory organs form an irregular central band near the 

 dorsal surface ; they are generally filled with the usual white opaque 

 granular matter. 



The distribution of the hairs is as follows : a pair of very long 

 ones each side on the above-mentioned shoulder pointing backwards, 

 and almost reaching the posterior margin. A strong hair standing 

 outward from the lateral margin, between the first and second, and 



