586 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.47. 



scheme of musculature is similar to that of the female. But where 

 there is not only flexion but also complete fusion {Clavella, Clavellisa, 

 etc.) the musculature is entirely changed. Wo no longer find any 

 dorsal and ventral body muscles, or any special respu-atory muscles, 

 but all the movements of the body are accomplished by means of 

 muscles connected with the appendages. The male of Clavellisa 

 may be taken as an example (fig. 7). The muscles of the left side 

 only are given in the figure, and it is to be understood that each is 

 dupUcated on the right side. It will be noted that there are single 

 muscle strands connected with the first and second antennae {an' , 

 an"), larger and more powerful single muscles connected with the 



first maxdlae {mx') and the mandi- 

 bles {mad), whUe there are three 

 stout muscles attached to each sec- 

 ond maxilla {mx") and maxilliped 

 {mxp). Each of these muscles is 

 inserted in the base of the append- 

 age to which it belongs and runs 

 diagonally into the body to its 

 origin, somewhere on the dorsal or 



Fig. 8.— Doesal view of ejacuiatoey mus- lateral walls. 



CLES (em) AND SPEEM EECEPTACLE (sr) OF * n .1 .• • ji 



AcHTHEEEs AMBLOPLiTis. ^11 thc ucccssary motions m the 



male are accomplished by these ap- 

 pendage muscles. In these pigmy males, therefore, the last vestige 

 of segmentation, namely, the interrupted longitudinal muscle bands, 

 has completely disappeared. 



RESPIRATION. 



There is in this family nothing which resembles, or functions as, 

 a respiratory organ; there is not even the opening and closing of the 

 anus and rectum (anal respiration) so prevalent among the free- 

 swimming forms and in the CaUgidae and Ergasilidae. 



In the female there are no oblique muscles attached to the sides of 

 the rectum, and in the male there is no anal opening, so that such a 

 method of respmT.tion is impossible in both sexes. 



Apparently the only means of aerating the blood is through the 

 body walls, which are comparatively thin. Furthermore the demands 

 for aeration have been reduced to a minimum in these parasites, 

 who have lost all freedom of motion, whose food is very easy to digest, 

 and whose circulation is extremely crude. 



CIRCULATION. 



There is no heart nor any blood vessels in the Lernaeopodidae; 

 there are not even any lacunae through which the blood might flow. 

 The body is virtually a bag, in the cavity of which are suspended the 

 various organs, while the spaces around them are entirely free, and 



