so. 3 BURGESS SHALE FOSSILS WALCOTT 45 



IVaptia circttlaris, new species -'4 



Fig. 3. (X2.) Side view of a flattened specimen illustrating the form 

 of the carapace, one side of which has been crushed upward 

 and backward. The exopodites of the thoracic limbs appear 

 to have the same structure as those of Wapfia fieldensis. 



Mollisoiiia :' vara Walcott 2~ 



Fig. 4. (X--) A retouched figure of a most excellent specimen. 



Plate 22 



p.\c:e 



Marrclla splcndcns Walcott 28 



Fig. I. (X4.) Dorsal view of a specimen showing the mandibles, the 

 antenna on the left side extending down beside the mandible, 

 and the exopodites referred to the maxillae and maxillulae ; 

 what may be the endopodite of the maxillulae is shown on the 

 right side below the fringing filaments of the exopodite of the 

 maxilla. 



2. (X4-) In this ventral view the mandibles have been pushed 



forward so that the mandible and antenna on the right side 

 are in a vertical position and side by side, and the endopodites 

 of the maxilla and maxillula are in advance of their natural 

 position ; on the left side two endopodites of thoracic limbs 

 are faintly outlined. 



3. (X4-) Ventral view of a specimen in which the joints of the 



mandibles have been crowded together and somewhat short- 

 ened ; the proximal joint on the right side is well exposed by 

 the labrum having been pushed forward ; the inner margin 

 of the joint is serrated but not quite as clearly shown as on 

 the specimen represented by fig. 6. 



4. (X4-) The dorsal view of this specimen is illustrated to show 



the position of the antenna on the right side which is the 

 same as the antenna on the left side in fig. i, and on both 

 sides in fig. 5 : the position of the mandibles is also well 

 shown. 



5. (X4-) Ventral view showing the position of the mandibles 



beside the labrum, also the exopodites of the maxillae and 

 maxillulae posterior to them ; the antennae appear to have 

 been torn away in the crowding forward of the mandibles. 



6. (X 4-) Ventral view of a specimen showing the mandibles, the 



one on the right side preserving the pro.ximal joint with a 

 serrated inner margin. This mandible has been colored white 

 in order to bring it out more clearly in the reproduction ; the 

 thoracic exopodites are very clearly shown on both sides, the 

 endopodites having been largely exfoliated. 



7. (X 4-) Ventral view of a specimen preserving a complete man- 



dible on the left side, also several endopodites of the thoracic 

 limbs, and on the right side six joints of the mandible and a 

 few imperfect thoracic endopodites, which are exposed on both 

 sides by the exfoliation of the exopodites. 



