60 



Dr. H. A. Pilsbry, whom I had the pleasure of meeting 

 in Philadelphia last year, on looking at my specimens, was 

 much interested in this strange feature, and considered that 

 it well justified the separation of the South Australian form 

 from that found in the other States. 



Owing to the imperfections of both figure and descrip- 

 tions, it is necessary to append a full description. As far as 

 I am aware, Loricella angasi has only been figured in Dr. 

 Pilsbry 's famous monograph on Polyplacophora, pi. 51, fig. 9, 

 the drawings of which were made by Emerton, for Carpenter, 

 Dr. Pilsbry having no specimens to examine. In that figure 

 short hairs are shown on the anterior portion of the girdle, 

 but Dr. Pilsbry appends a note, "The hairs shown in the 

 girdle, in fig. 9, are foreign to it." 



Loricella angasi, H. Adams and Angas. 

 (Proc. Zool. Soc, 1864, p. 193.) 



General appearance. — Shell broad, carinated ; when alive 

 the whole of shell is usually covered with limy encrustations 

 and growing algae ; when these are cleaned off the lateral areas 

 are seen to be strongly raised and covered with close wavy 

 ribbing. The pleural areas, closely covered with longitudinal 

 wavy riblets; girdle, broad, the anterior portion is double the 

 width of the posterior and is crenulate at margin, but in adult 

 specimens this crenulation in the anterior portion is produced 

 in a number of flattened finger-like processes, up to 4 mm. in 

 length, and extending beyond the margin of the girdle. 



Colour. — The anterior valve and lateral areas are terra- 

 cotta, with the exception of valve 2, in which the lateral area 

 is the same colour as the pleural area ; in the pleural and 

 dorsal areas the lighter markings are dull white, tinged with 

 olive, and the darker markings vary from brownish-olive to 

 light-brownish-olive. The girdle, while for the most part 

 olivaceous, the margins and various patches are rosaline-purple, 

 but this may be due to a red alga. Inside of valves white. 



Anterior valve. — Very large and broad, strongly convex 

 in the middle, apex recurved, the whole valve covered with 

 closely-packed wavy riblets. The posterior margin finely 

 serrated. The inside has 8 slits nearly equidistant, teeth 

 finely pectinated, and on the upper side fluted. 



Posterior valve. — This is the smallest of the valves, the 

 mucro terminal, and much elevated; the posterior half of this 

 valve is recurved, diagonal ridges strongly raised, and the 

 dorsal ridge well marked. The whole valve covered with wavy 

 longitudinal ribbing, with transverse growth lines. 



Central valves. — Lateral area strongly raised and sculp- 

 tured with closely-packed wavy ridges similar to the anterior 

 valve, broken at irregular intervals by deep sulci following 



