On the Determination of Bryozoa. Btj A. W. Waters. 115 



mandibles of the avicularia should also be taken into consideration, 

 but as I had only examined and made pref)arations of a limited 

 number I did not feel justified in publishing anything about them, 

 but called the attention of many of my friends who were working 

 at the Bryozoa to the use they were likely to be, and showed them 

 drawings. 



Since then I have been engaged in the examination of fossil 

 Bryozoa, in which of course the chitinous organs are not preserved, 

 but the careful examination of the oral aperture, from which con- 

 clusions as to the shape of the operculum can be drawn, has been 

 the basis of my work with the Australian fossils, and I have pre- 

 pared the opercula of a large number of Catenicellm and other 

 genera represented by fossil allies, so that although we may never 

 find the chitinous organs fossil, yet the study of them may be of 

 the greatest value paleontologically. 



Mr. Busk, when working at the ' Challenger ' material, in 

 consequence of my short paper, took up the examination of the 

 chitinous organs, and to him we must give the credit of first 

 applying the form of the mandible in specific determination, the 

 results being especially valuable in the genus Cellepora; and 

 Professor MacGillivray has also shown their value in. the genera 

 Cellaria and Betepora* 



The most important feature of Mr. Busk's report on the 

 * Challenger ' Bryozoa is undoubtedly the use he makes of the 

 chitinous organs, but as some of his generalizations are evidently 

 based upon incomplete series, I take the opportunity of adding to 



Fig. 31. — Avicularian maniUble of Cellepora costata MacG. = retnsa var. caminata 



Waters, Naples. 

 „ 32. „ „ C. avici'laris Hincks, Naples. 



„ 33. „ „ C. sardonka Waters, x 2.50 & 85. Naples. 



„ 34. ,. „ Cribrilina radiata var., Niiples. 



„ 35. — Spatulate avicularian mandible oi Schizoporella auriculata Hass., Naples. 

 „ 3fj.-»-0ral „ „ „ „ „ 



„ 37. — Avicularian manilible of Cellepora verruculata Sm., Naples. 

 „ 38. „ „ C. diijitata Waters, Capri. 



„ 3'J. „ „ C. sardonica Waters, Naples 



„ 40. „ „ Membranipora cnrvirodris Hincks, Naples. 



„ 41. „ „ M. tenuirostris Hincks, Naples. 



„ 42. „ „ M. angulosa Rss., Naples. 



„ 43. „ „ M. Flemiiifjii Busk, x 250 & 85. Durham. 



„ 44. „ „ Adeonellapoli/stomellallBB. X 250 & 85. Naples. 



h, operculum of ditto.- 



All are shown magnified 85 times, being the same as that a<l()pto(l in my 

 paper " On the Use of the Opercula," &c., but as some avicularia are too .small 

 to show (Jotail this size, ihey arc given as fig. a magnified 85 times, and also 

 fignn d increased t(j 250 times. All were examined with a power magnifying 

 500 times. 



• " Description of Now or Little Known Polyzoa," Trans. Hoy. Hoc. Victoria, 

 XX. (1883) lip. 103, pl.s. 1 and 2 ; also in vol. xxii. (from advance copies). 



3 E 2 



