Natural History of East Flnmarh. 591 



is often developed an acute mandibled aviculariura, some- 

 times a raised process without avicularium (see Smitt, figs. 25 

 & 27, and Loreuz's figure) ; and when the zooecium below 

 a median avicularium bears an ooicium, the latter is tilted 

 up, and the avicularian process is seen behind it at a lower 

 level. In older specimens without oojcia the interzooecial 

 space has a raised wall inclosing a hollow space within it, most 

 variable in shape (square, oblong, triangular, round, or cre- 

 sccntic), the avicularium is no longer seen, but in one or two 

 instances I have seen the space covered with a membrane with 

 a central opening or pore, in others instead of any hollow a 

 large nodule with the avicularium on one side of it. The 

 zocecia in this species are smaller than ia C. unicornis, var. 

 arinifera, from which it is most readily distinguished by the 

 lateral avicularia having the mandible directed upwards and 

 inwards (instead of downwards and outwards) : it seems but a 

 small difference, but would appear to be constant. 



When C. Sophia is found living in exposed situations, such 

 as the shell of living Neptunea despecta, spines are not ordi- 

 narily seen, and the margin of the zooecia becomes much 

 thickened and strongly granulated. 



The variations are very great. In some Spitsbergen 

 specimens, for which I am indebted to Smitt, the whole 

 space between the zooecia is elevated into a flat-topped, nearly 

 square, slab-like plate ; at each corner of the slab is a lateral 

 avicularium, those at the bottom of the slab belonging to 

 tiie zooecium below, and those at the top belonging to the 

 alternating zooecia on either side above ; in front is seen the 

 arch of the ooecium, which thus would seem to lie under 

 the slab. 



Varanger Fiord {A.M.N.), Svserholt [Nordgaard). Other 

 specimens in my collection are from " Finmark " and Spits- 

 bergen {Smitt), Nortii Cape {A.M.N.), west of Holstein- 

 borg, Greenland, in 57 fathoms ('Valorous,' 1875), Davis 

 Strait [A. Hancock), Gulf of St. Lawrence (Whiteaves). 



Callopora unicornis, Fleming, var, arniifera, Hincks. (PI. 

 XIII. figs. 10, 11.) 



1867. Membranipora lineata, forma aniericana, Smitt, " Kritisk Fiir- 



teckning, &c." p. 366, pi. xx. fig. 31. 

 1880. Memtjranipora armifera, Plincks, " Contrib. gen. hist. Polyzoa," 



Ann. & Mag. Nat. Hist. ser. 5, vol. vi. p. 82, pi. xi. fig. 5. 

 1892. Membranipora armifera, Hincks, " Polyzoa St. Lawrence," Ann. 



& Mag. Nat. Hist. ser. 6, vol. ix. p. loo, pi. viii. fig. 4. 

 1898. Membranipora Sophia, var. annifcra, Waters, " Observations on 



the Membraniporidee," Journ. Linn. Soc, Zool. vol. xxvi. p. 860, 



pi. xlviii. fig. 18. 



