CLASS GASTROPODA 
257 
slopes somewhat convex; surface apparently smooth except for well- 
marked grooves or wrinkles, indicating growth-periods. Under the micro¬ 
scope, however, an excessively fine reticulation is visible. The color is 
light buff, marbled all over with orange-red in various patterns, or entirely 
suffused with reddish; usually having a red stripe bordered on each side 
with buff. The anterior valve is twice as wide as long, crescentic rather 
than half-round. The intermediate valves are slightly beaked, their lateral 
areas slightly raised and having stronger concentric wrinkles than the cen¬ 
tral areas. Posterior valve having a rather elevated but obtuse median 
umbo. The interior is bright pink. The sutural plates are wide, large; 
the jugal sinus is deep, narrow, and angular. The insertion plate of the 
anterior valve has 8-11 slits; intermediate valves normally 1 slit; posterior 
valve 7-11 slits. The insertion plates are sharp and smooth. The girdle is 
reddish-brown, covered with minute elongated scales. Length, 20; breadth, 
12 mm. Alaskan specimens grow to the length of an inch. (Tryon and 
Pilsbry, Manual of Conchology.) 
Type in Linnaeus Society, London. Type locality, Oceano septentrio- 
nali instar Patellae affixa. 
Range. Arctic Ocean to Monterey, California. Circumboreal. 
Described as Chiton ruber. 
Lepidochitona sitkensis Middendorff, 1846 
Bulletin, Imperial Academy of Sciences, St. Petersburg, 6:121. Malacologia Rossica, 
PI. 13, figs. 1, 2. 
Chiton minutus, testa oblongo-ovali subcarinata, exroseo flava, amculis 
ferruginosis irregularibus notata, subtus intense rosea.Valvae 
laeves, mucrone parum prominente, striis incrementi irregularibus; . . . . 
areis lateralibus indistinctis.Valve antica dentibus 9. 
Valva ultima margine postico dentibus numero 10, lateralibus majori- 
bus.Valvarum intermediarum dentes laterales duo; mucrones 
apice detritu stratum testae subjacens porosum ostendunt; areae centrales 
infcrne spectatae; antice pulchre porosae; postice vero pori in sulcos 
transversos extenduntur. Pallium marginale latum albidum glaberrimum. 
Branchiarum series ab initio tertiae quintae partis totius corporis longi- 
tudinis ad visinitatem ani usque porrigitur. Lamellulae branchiales circiter 
26.LongitudoO.il decim. (Middendorff.) 
Shell depressed, smooth, the lateral areas indistinct, under a lens seen 
to be sparsely granulose; reddish. Anterior valve having 8, posterior 10, 
central 1 slit. Length, 10; width, 6 mm. (Tryon and Pilsbry, Manual of 
Conchology.) 
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