456 PEOF. A. DENDT ON SOME POINTS IN 



structure of the test, being presumably caught up in its growth. 

 The probable use of these spicules in Saddonia, as in the other 

 genera mentioned, would seem to be for the stiffening and 

 support of the sarcode, whether within the chamber-cavities or 

 at the points of extrusion, as in Polytrema. 



EXPLANATION OF PLATE 28. 



Fig. 1. Haddoniatorresiensis, gen. eta'Q. laoy. A typical specimen. Apertural 



valve situated on the upper surface of the test. X 6. 

 Fig. 2. Haddonia torresiensis. A specimen with a spiral commencement. The 



end of the test is broken away, and shows the open labyrinthic 



structure. X 6. 

 Fig. 3. Haddonia torresiensis. Apertural end of test, showing valve-like 



opening ; the valve in this instance is situated nearer the attached 



surface of the test. X 9. 

 Fig. 4. Section through the shell- wall of Haddonia torresiensis. o, the external 



surface of the test ; i, the inner surface ; b, the hyaline shell-layer ; 



p, the coarse pores in the shell-wall. X 60. 

 Fig. 5. A fragment of the dried sarcode of Haddoiia torresiensis, highly 



magnified, c, irregular cavities in the sarcode, probably due to drying ; 



s, a sponge-spieule embedded in the sarcode. X 332, 



On some Points in the Anatomy of Caudina coriacea, Hutton. 

 By Aethue Dendt, D.Sc, F.L.S., Professor of Biology in 

 the Canterbury College, University of New Zealand. 



[Eead 2nd December, 1897.] 



(Plate 29.) 



The occurrence of small projections arranged, usually in groups, 

 around the anus * has been known for a long time, but compara- 

 tively little light has yet been thrown upon their exact nature. 

 It has, indeed, been recognized that these projections are of two 

 kinds, anal teeth and anal papilla:. The former occur as cal- 

 careous plates or scales, radial or interradial in position f ; the 



* I use the term anus in accordance with the usual custom, though cloacal 

 aperture would doubtless be more appropriate. 



t Vide Ludwig's " Echinodermen " in Bronn's ' Klassen und Ordnungen des 

 Tr-hiereichs,' p. 141. 



