10 Transactions of the Society. 



cammina sphasrica does not appear to be found. In the North 

 Sea Crithionina mamilla occurs at many stations with Saccam- 

 mina, but it attaches itself indifferently to any object — preferably 

 to Astrorhiza, and it might just as reasonably have been regarded 

 as an initial stage of that form. (Plate III, figs. 5-7.) 



At the majority of stations from which Saccammina has been 

 recorded by us, Crithionina mamilla is absent, its distribution 

 being apparently confined to those localities in which there is a 

 maximum of fine muddy deposit, and therefore a minimum of 

 current action. From the nature and characteristics of Dr. Ehuni- 

 bler's specimens his material would appear to have been derived 

 from dredgings taken under similar conditions — i.e. from waters 

 which are very still in spite of their moderate depth, as is usually 

 the case in most of the Norwegian fjords. 



The work of Dr. Ehumbler (6) is perhaps one of the most 

 important contributions which have been made to the specialized 

 literature of the Foraminifera, and it is difficult, if not impossible, 

 to give in this place an adequate impression of its value. We have 

 purposely avoided the consideration of his researches in connexion 

 with the chemical constituents and reactions of the test, and 

 of the contained sarcode-body and its nuclei, with regard to its 

 reproductive processes and stages. We prefer to confine our 

 examination of his work to the test itself and its mechanical and 

 physical construction. 



He states that either on two {6, p. 436) or on several (p. 437) 

 occasions he has observed tests bearing two orifices situated upon 

 their characteristic nipple-shaped protuberances. This variation 

 from type we have not observed in our material, but in any case, 

 such observations cannot be regarded as of any value, as monstrous 

 specimens, bearing two or more apertures, are of constant occurrence 

 in all genera and are only to be regarded as abnormal growths. He 

 suggests, on the implied authority of Schulze, of Brady, and of 

 Haeusler, that Psammospheera possesses obscure but veritable 

 apertures. In this matter again we differ from him and do not 

 recognize such a suggestion in the authorities which he quotes. 



As regards the possible existence of foramina in the cement- 

 substance that binds together the constituent sand-grains of ^^c- 

 cammina, he concluded that these were absent, but it is difficult to 

 follow his reasoning and conclusions founded on an examination of 

 the perforations in the calcareous tests of other species to which he 

 ascribes a diameter of * 00524 mm. : and still more his experiments 

 made with specimens filled with oil of cloves and then immersed 

 in alcohol only so far as to leave the pylomtubus exposed. 



With his theory of the generation of Saccammina by means of 

 primordial chambers of white cement-material and sponge-spicules 

 attached around the pylomtubus of adult shells we have already 

 dealt, and we see no reason for assuming that these microscopic 



