[44] Bull. Mus. C. Z. Harv. iv. p. 378.
[45] W. Harte, Proc. Dubl. N. H. Soc. iv. p. 182.
[46] See on the whole subject of threads G. S. Tye, Journ. of Conch. i. p. 401.
[47] Zoologist, ii. p. 296; iii. p. 833; iv. p. 1216; iii. p. 1036; iv. p. 1216; iii. p. 1037.
[48] Ann. Nat. Hist. ii. 1838, p. 310.
[49] H. W. Kew, Naturalist, 1889, p. 103.
[50] Zeit. wiss. Zool. xlii. p. 203 f.
[51] Sci. Trans. R. Dubl. Soc. (2) iv. p. 520.
[52] Zoologist, iv. p. 1504; iii. p. 1038; iii. p. 943.
[53] H. W. Kew, l. c.