EXPLANATION OF PLATE XIII. 



Figure 65. — Autolytus comutus, (p. 590;) an asexual individual, from which a male is 

 about to separate ; dorsal view, enlarged about six diameters ; A, A, A, 

 antennae of the former; C, C, C, C, two tentacles and one tentacular 

 cirrus on each side, followed by the dorsal cirri ; F, the intestine ; d, the 

 long setse and dorsal cirri of the male. 



66. — The same ; anterior part of a female, more enlarged ; the letters as before ; 

 b, the eyes; e, the eggs; /, the intestine ; 3, one of the appendages of 

 the anterior region of the body ; c, the dorsal cirrus; 7i, the setigerous 

 tubercle, supporting hooked setse. 



67. — Diopatra cuprea, (p. 593 ;) head and anterior part of body, showing part 

 of the branchiae ; side view. 



68. — The same; ventral view, showing the mouth open and jaws thrown back. 



69. — Lumbriconereis opalina, (p. 594 ;) anterior part of body ; dorsal view. 



70. — The same ; lateral appendage and setse. 



(Figures 65 and 66 were copied from A. Agassiz ; 6", 68, 69 were drawn from nature by J. H. Emer- 

 ton ; 70, by A. E. Verrill.) 



