65 



The spear-heads vary a good deal, both in size and shape. 

 Some are long and lanceolate, sharply pointed ; others are 

 globose and blunt; many are oblique, slightly scimitar- 

 shaped; all are equally white and glossy. 



As before stated, the longer hairs, or tubes, take their 

 rise in clusters fairly equidistant midway across the 

 girdle, and are placed opposite the strange finger-like pro- 

 cesses, those nearest the shell measuring up to 4 mm. in. 

 length, but becoming shorter and shorter as the margin of 

 the girdle is approached until along the centres of the finger- 

 like processes they are nearly all unstalked, and form a closely- 

 packed row of porcelainous spear-heads, some still partly 

 buried in the girdle. Along the front of the finger-like pro- 

 cesses the spear-heads are small and scattered, not adhering to 

 the mid-line, as is the case further back. 



To the question, What is the function of the strange 

 coarse hairs, or tubes, and their peculiar apices, and what 

 purpose do they serve ? I can find no definite answer. I do 

 not think their purpose is either that of decoration or pro- 

 tection, for in life the shell and girdle are covered with 

 growth. Also, it is most strange that the allied form occur- 

 ing in the other States should not have similar spear-headed 

 terminals to the hairs ; possibly they do have them at an 

 early stage, and dispense with them in the adult form, though 

 in the specimens examined there is nothing to suggest this. 



One is struck with the points of similarity between the 

 genus Loricella and the North American genus Placiphorella, 

 belonging to the family Mopaliidae. Mr. S. Stillman Berry, 

 in his valuable paper on "Chitons taken by the United States 

 Fisheries steamer 'Albatross' " (U.S. Nat. Mus. Proc, vol. 

 54), figures several of this genus which exhibit the following 

 similarities : The girdle is much wider in front than behind, 

 the foot is short and broad, and for the size of the shell small ; 

 the girdle is adorned with remarkable hairs, although these 

 are structurally very different, but in pi. 9, fig. 6, he shows 

 the presence of some minute spicules that are somewhat 

 similar, though much smaller, to the "spear-heads" on 

 Loricella angasi. 



I have presented the type of Loricella torri to the South 

 Australian Museum. 



DESCRIPTION OF PLATE X. 



Fig. 1. Shell of Loricella angasi, Ad. and Ang., x£, showing in 

 girdle, slit, fringed margin, and spicules, p. 60. 



,, la. Girdle of same, x6, showing finger-like processes and 

 spear-headed spicules. 



,, 16. Girdle and part shell of Loricella torri, n. sp., x6, p. 62. 



,, lc. Loricella angasi, Ad. and Ang., x2, underside showing 

 animal. 



,, Id. Spear-headed spicules and girdle margin of same, x20. 



D 



