GENUS HYALOLAMPE— HYALOLAMPE FENESTRATA. 271 



sac, resembling the exterior of the former specimens, but filled with a clear 

 liquid and containing a large ball of granular protoplasm. This was nearly 

 homogeneous, and presented several vacuoles at its periphery, which from 

 time to time would successively collapse and again reappear. The mass 

 exhibited feeble movement in a change of form, but finally it became quiet 

 and all its vacuoles disappeared. 



Another individual, fig. 16, was like the preceding; but the inner 

 globular mass of protoplasm was more sharply defined, and exhibited a 

 distinct nucleus. A fourth individual presented the same appearance, 

 excepting that the inner ball contained a few scattered green corpuscles. 



The specimens of Acanthocystis above described appear to me to be 

 most nearly related to the Acanthocystis Pertyana of Mr. Archer.* They 

 also approximate in character with the Acanthocystis aculeata of Hertwig 

 and Lesser,f but in this the spines are much larger and coarser. I suspect 

 also that the animal represents one of the stages of the form described by 

 Perty as Actinophrys hrevicirrhis.% 



HYALOLAMPE. 



Greek, hualos, crystal; lampe, foam. 

 Hyalolampe: Greeff, 1869. Pompholyxoplirys: Archer, 1869. 



Animal spherical, composed of a finely granular protoplasmic mass 

 mingled with variable proportions of colored granules and vacuoles, and 

 containing a central nucleus. Body invested with a thick layer of loosely 

 coherent, minute, clear, silicious globules. Pseudopods few, radiant, 

 exceedingly delicate, filamentous, and non-granular. 



HYALOLAMPE FENESTRATE 



Plate XLV, fig. 9. 



Hyalolampe fenestrata. Greeff: Arch. mik. Anat. v, 1869, 501, Taf. xxvi, Fig. 37 ; xi, 1875, 18, Taf. i, Fig. 6, 



7.— Hertwig and Lesser: Ibidem, x, 1874, Supp!. 221.$ 

 Pompholyxoplirys punicea. Archer: Quart. Jour. Mio. Sc. ix, 1869, 386, pi. xvi, figs. 4, 5 ; x, 1870, 105, pi. xvi, 



fig. 4; xvi, 1876, 375. 

 Hyalolampe exigua. Hertwig and Lesser : Arch. mik. Anat. x, 1874, Suppl. 222, Taf. iv, Fig. 6. 



Body usually more or less yellowish, brownish, or reddish. Investing 

 silicious globules commonly in three layers. 



'Quart. Jour. Microscopical Science, 1869, 252, pi. xvi, fig. 1; 1870, 32. 

 t Archiv f. mikros. Anatomie, 1874, Suppl. 201, Taf. iv, Fig. 2. 

 } Kennt. kleinst. Lebensformen, 1852, 159, Taf. viii, i, Fig. 7. 



§ The names of Hyalolampe and Pompholyxoplirys are nearly cotemporary, and I have followed 

 Hertwig and Lesser in the choice of the former as being the more euphonious. 



