PLATE XL 

 no. 



1 . — A magnificent Polycystin, from Cambridge, Barbados. It measures 

 .0214 in heiglit, viz., the ball .0028, and .0186 from the ball to 

 the base, where several more squares appear to have been broken 

 off, — about 18 to 20 rows of squares, like windows ; inside some 

 of them a very fine internal network is seen ; througli others 

 appear a faint reflection of the bars on the opjjosite side of the 

 oljject: the effect of this, viewed Lii the Binocular (half-inch 

 objective) is very striking. 



2. — Eucyrtidium tubulons, Ehr., measures .01 feet long, .0028 broad, 

 from Peak of Teneriffe, Barbados. Quarter-inch objective. 



3. — Stylosphnera (?) Ehr., measures .01 high, curiously beset with sharp, 

 spear-like spines, and covered apparently \\dth pointed linobs or 

 warts. Some of the Barbados Polycystins suggest an idea as if 

 their perforations either may have been, or miglit have become 

 occupied by these sort of projections, which, when broken off, 

 leave holes, and being hollow, would still permit the protrusion 

 of the so-called Psendopodian threads, which Professor J. Miiller 

 says "one may conjecture (Vermutheny to be the means by 

 which the Polycystins imbibe nourishment, although their con- 

 nexion with the Sarcode substance of the bodies, requires more 

 clear elucidation. In the TliallassicoUen and Polycystina, they 

 can only be traced as far as the skin-like capsule of the flabby 

 jjart lying under the flint corselet. 



4. — Dictyospiris (?) jirobably the same object as fig. 2, on plate II > 

 turned on the reverse side. Ehrenberg calls this "Ruckseite,' 

 and the other with the larger openings, "Mouthside," — from 

 Cambridge, Barbados. 



5.— Spongolithis acicularis, (Mik. Taf. XXXVI, fig. 47) a Pliytohtharien 

 of Ehrenberg. 



6. — Amphidiscus verticillatus, Mik. Taf. XXXVI, fig. 45, classed by 

 Ehrenberg as " Phytolitharia," — of plant growth. 



