84 American Quarterly Microscopical Journal. 



sand-grains, and bears several (4-6) tubules near its larger end. 

 These minute tubes have the shape of horns, but by strong 

 magnifying power are seen to be open at (what with lower 

 power seem to be) their points, from which very slender pseu- 

 dopods are occasionally projected. Their substance appears like 

 diatomin, and is an outward continuation of an inner lining, 

 upon which the sand-grains are incrusted, as may be best 

 observed on the margins of broken shells. The question 

 arises, for what purpose are these small, spiny tubes ? They 

 probably serve as spines or bayonets for weapons of defence, 

 as do the diatom shells I have observed fixed erect upon 

 the shell of another species of rhizopod, probably 

 -Diffli/ii^ia bacillariarum, Perty, but it is likely that they also serve 

 some other purpose not now understood. Besides this, I have 

 studied, in this country, several specimens representing two 

 well-marked new species as follows : Echinopyxis tentorium, nov. 

 sp. (Plate VIII., Fig. i, a. b.). The test conical with a concave 

 base, and bearing one tubule on its apex ; opening subcentral. 

 Its only decidedly specific characters belong to the shell, which 

 presents the general form of a tent, or inverted funnel, and is 

 so opaque that nothing can be seen of the amoeboid animal 

 within, except its pseudopods, which are sometimes, though 

 seldom, extended from beneath, serving especially for locomo- 

 tion and prehension. Also, a delicate plasmic point is occa- 

 sionally projected from the single tube above. Speci- 

 mens of this species are found on the muddy and sandy 

 bottoms of creeks and ponds in New York. Echinopyxis liemi- 

 spherica, nov. sp. (Plate VIII., Fig. 2). Test hemispherical, 

 depressed ; tubules several (3-7), more or less elongated and 

 crooked, with large distal openings ; the main aperture sub- 

 central. This form is found also on the muddy and sandy 

 bottoms of ponds and creeks in the same locality. The 



DESCRIPTION OF PLATE VIII. 



Fig. I. Tesi oi Echinopyxis tentorium ; a, elevation view,/', showing pseudo- 

 podal orifice in concave base x 450. 



Fig. 2. Test of E. hemispherica as seen from above, showing seven hollow 

 tubules, one with pseudopodi projecting x 450. 



p'ig. 3. Test of E. aculeata ; a, lateral, t>, dorsal view, showing four hollow 

 horns x 200. 



Fig. 4. Sectional view of Eitglypha tegitlifcra, with its protoplasm, pseudo- 

 pods, nucleus, and nucleolus, granulus, etc. 



