174 PHILIP p. CALVERT. 



Second accessory of the posterior depressor (flexor radii quinti Lend., additionnel 

 anterienr an abaisseur posterieur Pol.) is larger than the preceding, on the inner 

 side of which it lies, and is on the hinder part of the posterior depressor; it 

 arises from the lower part of the mesepinieron behind the origin of the posterior 

 depressor, and inserts by a cap-tendon into the wing-base below the post-costa, 

 almost side by side with the first accessory. 



Principal elevator of the front wings (tensor alse primte Lend., elevateur Pol.) is 

 a large muscle close to the middle line of the thorax and behind the anterior 

 depressor ; its origin is from the top of the mesothoracic neural canal and from 

 the inner side of the second coxal opening, and inserts by a more powerful cap- 

 tendon than that of any other muscle of this wing, on the extreme inner wing- 

 base from the costa to the median vein. A small muscle extends from its tendon 

 of insertion to the fulcral process. 



Anterior accessory elevator of the front wings (pronator alse primje Lend., addi- 

 tionnel anterienr an elevateur Pol.) lies between the principal elevator on the 

 inside, the posterior depressor on the outside, the anterior depressor in front, 

 and the posterior accessory elevator behind ; it arises from the upper, outer 

 margin of the .second coxal opening, and inserts by a cap-tendon into the wing- 

 base below the costa; the level of its insertion is not as far forward as that of 

 the anterior depressor. The tendon of this muscle is not cap-like in Calopteryx. 



Posterior accessory elevator (supinator alse primje Lend., additionnel posterieur 

 au elevateur Pol.) is behind the preceding; it takes origin from the upper, outer 

 margin of the second coxal opening immediately behind the origin of the an- 

 terior accessory elevator; it inserts by a pale tendon into the wing-base below 

 the subcosta. 



Adductor radii quinti aim primx (Lend.) arises from the mesonotum opposite 

 the level of the median vein, and inserts at the base of the post-costa. In front 

 of this muscle is the insertion of the posterior accessory elevator, behind it are 

 the insertions of the two accessories of the posterior depressor and on its outer 

 side is the insertion of the posterior depressor. 



Muscles of the Hind Wings. 



Anterior depressor of the hind wings (abductor alae secundae Lend., abaisseur 

 anterienr Pol.) arises from the inner, anterior part of the metinfraepisternum 

 and the apodeme between the second and third coxje ; it inserts by a cap-tendon 

 into the front edge of the anterior axillary callus, a little in front of the costa 

 and of the fulcral process. 



Accessory of the anterior depressor (pronator radii primi alse secundae Lend., 

 additionnel au abaisseur anterienr Pol.) is a very small muscle, arising by tendon 

 from the lower, anterior part of the metepisternum, very close to the apodeme 

 of the rudimentary first lateral suture ; its belly is short, terminating in a slender 

 cap-tendon which inserts in the wing-base immediately external to the attach- 

 ment of the anterior depressor. 



Posterior depressor of the hind wings (flexor alae secundae Lend., abaisseur pos- 

 terieur Pol.) arises from the hind part of the metinfraepisternum and the adja- 

 cent part of the metepimeron, inserts by a cap-tendon into the pleural membrane 

 of the wing-base below the median vein. 



First accessory of the posterior depressor (additionnel posterieur au abaisseur 

 posterieur Pol.) a small muscle, lies a short distance behind the preceding, aris- 

 ing by tendon from the hind margin of the metasternum, and inserting by a pale 

 tendon into the wing-base below the sub-costa. 



