CHALABOTHORACA 29' 



(b) Envelope of silicious elements and little or no plasma 



consisting of — 

 Imbricated discs. Pinaciophora, 



Silicious globules. (6) Pompholyxoiohrys. 



Extraneous silicious materials 



closely investing the body. (7) LithocoUa.. 



Extraneous eilicious materials 



separated from the body by 



a zone of liquid. (8) Elseorhanis . 



Tangential scales and radial 



spicules. (9) Acanthocystis. 



The genera numbered 4 to 9 are those of which 

 species have been recorded from the British Isles. 

 For comparison with the British forms figures of 

 Eaphidoci/stis and Pinaciophora are here reproduced 

 (Figs. 184 and 185). 



Genus 4. HETEROPHRYS Archer. 



Heterophrys Aechee Qrt. Jrn. Micr. Sci. (n.s.) IX, 1869,, 

 p. 267. 



Envelope thick," formed of mucilaginous plasma, 

 finely granular, having imbedded in it numerous 

 radial, chitinous spicules which project beyond its 

 periphery ; body spherical ; nucleus and endoplasm 

 placed eccentrically; pseudopodia straight, radiating, 

 their axes arising from a "central" granule." 



Archer in his diagnosis of this genus describes the 

 radial spicules projecting beyond the boundary of the 

 envelope as " marginal processes " ; these he recog- 

 nised as linear and hyaline in the case of H. myriopoda,- 

 but evidently had not been able to resolve them in 

 H. focJcei, in which species he called them " indefinite 

 and variously figured." In 1876, however, he describes 

 the outer envelope in this genus as " being superficially 

 drawn out into these superficial, linear, capillary and 

 acute pointed processes (spines, Hertwig & Lesser)." 



H. varians F. E. Schulze is a synonym for Nuclearia deli- 

 , catida [vide Vol. I, p. 110). 



