28 PKOCKEDINGS 01'' THE 11 ALACOLOGICAL SOCIETY. 



I liave associated with this beautiful Chiton tlie name of my friend 

 Miss M. K. Mestayer as a mark of her interest in this group. 



Genus Lepidopleukus. 



Lepidopleurus, Kisso : Hist. Nat. I'Eur. Merid., vol. iv, p. 1267, 1826. 



Type (by subsequent selection by Pilsbry, 1892), Chiton caje- 

 ianus, Poli. 



I am quite unable to accept the following species as a typical 

 Lepidopleurux^ and therefore designate it as the type of a new 

 sub-genus. 



Lepidopledrus (Terenochiton, n.subgen.) subtkopicalis, n.sp. 

 ri. II, Figs. 10, 17. 



Shell small, elongate oval, highly keeled, side slopes straight and 

 steep, girdle scaly. General coloration uniform, pale reddish-yellow 

 to brick; two specimens blackisli-brown. Anterior valve flattened, 

 Avith the apex elevated and slightly recurved, the anterior slope being 

 faintly concave ; the sculpture consists of minute pustules, arranged 

 in very close radial rows. Median valves have their lateral edges 

 almost stiaight, but somewhat raised ; the sculpture of the lateral 

 areas, which are diiferentiated by a slight fold, is simply pustulose, 

 with no defined arrangement; the pleural areas are sculptured with 

 slanting longitudinal rows of separated tubercles; from the edge of 

 the valve ten rows can be counted before they become ill-defined and 

 merging on the dorsal area. Posterior valve small, Avith the mucro 

 anterior and elevated, the lateral slope concave. Sculpture as in the 

 median valves. Inside coloration white. Insertion-plates absent. 

 Sutural laminae low and broad, liigher towards the outer edges of the 

 valves, sinus broad. Girdle densely covered with minute striated 

 scales. 



The preceding description is drawn up from a medium-sized 

 specimen, selected as type. Minute juvenile specimens show the 

 anterior valve, lateral areas of median valves, and posterior area of 

 posterior valve to be simply pustulose, without any defined arrange- 

 ment of the pustules, whilst the pleural areas of the median valves 

 are sculptui'ed with few well-defined longitudinal rows of tubercles, 

 and the dorsal area is almost smooth. In an old cra.ssate individual 

 the pustules have developed into raised tubercles upon the anterior 

 and posterior valves, and the dorsal area is strongly irregularly 

 tuberculose, the longitudinal rows of the pleural areas showing 

 indistinctly through tlie strong tubercles massing and somewhat 

 merging. Length of type 6-5, breadth 4, size of largest specimen 

 8 by 4'5 mm. 



Ilah. — Sunday Island, Kermadec Group. 



Station. — Living on the undersides of embedded dirty stones below 

 low-water mark. Only procured at Coral Bay on the east coast. 

 " A small Lepidopleurus was living under dirty stones below low 

 water. It was only on the underside of stones deeply embedded." 



