PLANKTONETTA ATLANTICA. 148 



Fig. 9. — Semi-diagram malic antero-posteiior section of the body of 

 Planktonetta atlantica, based on a camera lucida drawing, the central 

 capsule restored to its supposed connections. The intra-capsular protoplasm, 

 compact below, slightly vacuolated above, is greatly vacuolated laterally, the 

 meshes running out to the central capsule ; this lateral protoplasm is appa- 

 rent also in Fig. 1. Orally the thin central capsule is perforated by the pro- 

 cesses for attachment to the diaphragm. The diaphragm, which stretches 

 right across the shell, is thickened at its edge so as to present a triangular 

 section ; it is inserted above into pits of the shell, and below has been drawn 

 as if either continuous with or inserted into the central capsule. Near its 

 anterior border the diaphragm is perforated by a bundle of tubes ; by these 

 the intra-capsular protoplasm communicates with the anterior mass of extra- 

 capsular protoplasm which is free from phseodial corpuscles. Through this 

 mass and through the whole phseodial complex runs the skeletal meshwork 

 produced by the branching of the various spines. Only portions of this have 

 been drawn ; it supports the protoplasm, and the phseodial corpuscles lie in 

 vacuoles in its meshes, x circa 120. 



Pig. 10. — A process for attachment of the intra-capsular protoplasm to the 

 diaphragm, perforating the central capsule, x 520. 



Fig. 11. — Portion of the skeletal meshwork of the phaiodium, produced by 

 the branching of three stouter spines. Slight webs occurring at the more 

 important nodes have been omitted from the drawing, x 280. 



Fig. 12. — Brown corpuscles of the pliaeodium, with various inclusions 

 (p. 139). X 520. 



Fig. 13. — Segmenting varieties of the clear corpuscles of the phaeodium 

 (p. 140). X 520. 



Fig. 14. — Segmented corpuscles of the phseodium from a specimen in 

 which the majority of corpuscles ranged between stages represented in c and d. 

 In e are represented three isolated segments from such a morula as d, show- 

 ing their attachment centrally and the darker stained area peri[)herally. 

 X 520. 



Fig. 15. — Organism from the phseodium. x 520. 



