THE MORl'HOLOGY OF THE OHEIl.OSl'OMATA. 343 



1898. Waters, A. VV. — "Observations on Mcnibranii)oritla;," ' Journ. Linn. 



Soc.,' xxvi, p. GSl. 

 1900. Waters, A. W.—" Bryozoa from Franz-Josel' Land," 'Journ. Linn. 



Soc.,' xxviii, p. 43. 



EXPLANATION OF PLATES 15—18, 



Illustratiug Mr. Sidney F. Harmer's paper " Ou the Mor- 

 phology ot" the Cheilostomata," 



Reference Letters. 



tir. Marginal areolae, acic. Avicularium. b. Pulypide-ljud. b.b. Brown 

 body. b.ep. Basal epitheca. bullr. Buttress of operculum, ca. Caecum of 

 stomach, calc.p. Calcareous pa|)illjfi. cond. Condyle, or cliitin surrouudinj; 

 tlie decalcified condyle, c. p. Communication |)ore. c. s. Compensal ion-sac. 

 crypt. Cryptocyst.. depr. Depressor muscle of frontal membrane, div . \)'wa\'\- 

 cator muscle of operculum, d. w. Distal wall of zooecium. ep. E|)itlieca. 

 ep. c. Cavity beneath ci)itlieca. /. Membranous fenestra. /. b. Frontal bars or 

 costules. Jl. Vertical flange of operculum, f. m. Frontal membrane. /. s/i. 

 Frontal shield. /. .s/i. d. Distal lobes of fronlal shield, in/, civic. Infra-avicu- 

 lari.iu compartment, j. Chitinous joint, lb. Labium. /. /•. Lateral recess. 

 m. c. Marginal cavity of frond. m. p. Median pore. in.t. Median tooth 

 (lyrula) of Smittia. vccl. Occlusor muscles of o|)erculum. op. U|)erculum. 

 op. gl. Opercular glands. oi\ Ovicell. p. Pores, p. c. rore-ehambers. 

 /;. d. Parieto-aiaphragmatic muscles, p. m. Parietal muscles. /;. mJ Distal 

 grou|) of parietal n)uscles. /;. v. m., p. v. m! Parieto-vaginal muscles and 

 bands. /;. w. Proximal wall of zooecium. p. z. Primary zooecium. r. m. 

 lletractor muscles of |)olypide. *., s.' Suture in calcareous wall. scl. Chitinous 

 sclerite. sp. Spine, sup. acic. Supra-avicularian compartment, t. Tentacles. 

 A 5. Tentacle sheath, t^. Vitta. uef*^. Vestibule (— diaphragm), r.' Daughter- 

 zocecium. 



Fig. 12 (PI. 15) and Figs. 43, 44, 50, and 51 (PI. 17) are diagrammatic 

 representations of the points respectively illustrated by them. Fig. 18 (PI. IG) 

 is X 1. Figs. 19, 20, 22, 32, 35, and 36 (PI. 10) were drawn to the same 

 scale (camera lucida, Zeiss, A obj.). Fig. 19 was not reduced, but the others 

 were reduced \,. All the remaining figures are more highly magnified (Zeiss, 

 C ol)j. ; afterwards X \). 



The specimens figured belong to the Museum ol ZmilD^^y at Candjiidge. 



