124 J. J. LISTER. 



In a species resembling Spiroloculina hyalina, F. E. SCHULZE, 

 R. Hertwig ((16), p. 46) found a single nucleus in young 

 specimens, and as many as seven in one with four chambers. 



Among the Peneroplince, Bi'TTSCHLi ((7), p. 80) found a 

 single nucleus in two specimens of PeneropUs pertusus, FoRSK., 

 but in a third specimen as many as four were present. The 

 central chambers of the specimens (which appear to have had 

 a mean diameter of 29 to 34 ^) are considerably larger than 

 those which succeed them, and are of the same size as that of 

 ScHACKO's specimen described above (p. 115). It is probable 

 therefore that they belonged to the megalospheric form. 



In an example of the type of PeneropUs planatus, F. and 

 M., whose central chamber measured about 27 /t in diameter, 

 and hence would appear to have belonged to the same form, 

 some eighteen or twenty nuclei were distributed through the 

 protoplasm. 



In Orbitolites complaiiata, Lamk., Butschli ((7), pp. 80-82) 

 described numbers of small round or oval or irregular nuclei in 

 which a reticular structure could be detected. They were most 

 numerous in the peripheral chambers, and might be absent from 

 the central chambers. As will appear below, this description 

 differs considerably from what I have found to be the usual 

 condition either in the megalospheric or microspheric form of 

 this species. 



III. Astrorkizidce. — In Dendrophrya radiata, Wright, 

 MoBius ((23), p. 13) found a single large nucleus, 66 /i in 

 diameter. 



IV. Lituolidce. — No record. 



V. Textularidte. Butschli ((7), p. 83) described two 

 specimens of this genus whose central chambers appear to have 

 measured about 12 /a in diameter, and which, therefore, may 

 have belonged to the microspheric form. In one, which was 

 young (nine chambers are represented), a single nucleus was 

 present ; in the other, which had fourteen chambers, at least 

 three were present. 



R, Hertwig ((16), p. 50) found a single nucleus situated in 

 the first formed chamber in a specimen of this genus with five 



