478 Mr. Edward Heron-Allen [May 21, 



scottii (SI. 37), which is built entirely of minute flakes of mica 

 cemented together at the edges. 



The finer Textularians are often beautifully hyaline, e.g. 

 Bulimina aculeata (SI. 38) and Bulimina suhieres (SI. 39). 



The Lagenidae (SI. 40) assume an infinite variety of beautiful 

 forms. 



Xodosaria fiUformis (SI. 41) is one of the most typical species of 

 its genus. 



Vaginnllna margaritifera (SI. 42). 



Frondkidaria alafa (SI. 43). 



CristeUaria costata (SI. 44). 



CristeUaria tricar incl la (SI. 45). 



Polyrnor2)]iina reghia (SI. 4G) is a very handsome representative 

 of a genus, which is frequently found attached to sand grains and 

 shells by fistulose processes (SI. 47). 



The Globigerinae (SI. 4^^), to which we have already alluded, are 

 often merely stages in the life history of Orbulma universa (SI. 40), 

 which we may break open and find in it the earlier Globigerina. 



'J'he Discorbinae are a vast family, of which I show D. vesicular is 

 (81. 50). 



Pulvinulina is represented by P. pauperata (SI. 51). 



The list closes with the Xummulitinae, to which the Xummulites 

 proper belong, as also the common shore forms PolgstomeUa crispa 

 (SI. 52), and P. maceJla (SI. 53), of which a specimen is shown 

 viewed by transmitted light. 



The object and significance of this variety of beautiful forms are 

 entirely obscure, but have engaged the attention of many biologists 

 both in the Foraminifera and in the Radiolaria.^ It must be 

 remembered that a Foraminifer like a Radiolarian is a unicellular 

 animal consisting solely of a microscopic globule of undifferentiated 

 protoplasm, vivified by a nucleus whose functions are httle 

 understood, but which are essential to the existence of the animal. 



This protoplasm is extended in the form of fine filaments which 

 intermingle freely with one another, called pseudopodia, and their 

 mechanical functions are locomotion and the capture of food. I 

 have made a series of photographs of a fine Gromia which emerged 

 from the mud in one of my tanks (SI. 54), climbed up the glass 

 (SI. 55) until it encountered a sea-weed stem, up which it crawled 

 (SI. 5G), and finally drew itself off on to the glass again by means of 

 its pseudopodia. It then got lost, l)ut on punching a hole in a piece 

 of black paper which was then gummed on to the glass and a strong 

 beam of fight directed through it (SI. 57), it came back into the 

 circle of light, apparently indicating that these creatures are sensitive 

 to light. 



1 Cf. F. Gamble in Rav Lankester, A Treatise on Zoology, pt. i. fasc. 1, 

 pp. 130, 131. 1909. 



