112 ISCHNOCHITON. 



warted, the warts lobed. Mucro anterior, slightly conspicuous. 

 Interior having the central valve with 1 slit, end valves 8-10 slits. 

 Eaves small; teeth acute ; sinus flat, very wide. Girdle imbricately 

 scaled. Length 15, breadth 7* mill.; divergence 110. (Cpr.) 



Panama. 



Lophyrus adamsii CPU., P. Z. S. 1863, p. 24. Lepidopleurus 

 adamsii CPU., P. Z. S. 1865, p. 274. 



The shells which I have drawn in figs. 51-55 of pi. 18, seem to 

 me to belong to this species rather than to J. dispar. They are 

 described below. It must be understood that the more minute 

 sculpture can be seen only under a compound microscope or a very 

 powerful lens. 



The shell is oval, rather low, the jugum rounded, side-slopes 

 nearly straight. Color dark olive mottled with lighter, or having 

 large whitish tracts on some valves ; the interior light blue, sutural 

 plates white. The central areas are closely sculptured with very 

 minute pointed whitish granules, arranged in oblique lines at the 

 jugum (fig. 52) but toward the sides or pleura a system of shallow 

 grooves with granulous inter-ridges curve fonvard from the diagonal 

 line, as shown in fig. 54, and at the left side of fig. 55. The lateral 

 areas and terminal valves have a coarsely reticulated pattern, 

 formed by impressed zigzag or irregularly lobed impressions, over 

 which a fine granulation extends (fig. 55.) 



The interior has 8-10 slits in the posterior valve, 1 in the inter- 

 mediate valves (fig. 53). Teeth sharp, smooth ; eaves very narrow. 

 The girdle was denuded of nearly all of its scales in both of the 

 specimens before me, but such as remain are large, solid. 



Length 14, breadth 8i mill. 



I. TENUISCULPTUS Carpenter. Unfigured. 



Shell similar to L. adamsii; olivaceous, minutely variegated with 

 paler and darker color. Entire surface minutely granulose ; lateral 

 areas scarcely defined; sutures spotted with white ; mucro anterior, 

 rather conspicuous, the slope behind it concave. Interior as in L. 

 adamsii. ( Cpr.) 



Panama. 



Chiton dispar C. B. AD., Cat. Panam. Sh. no. 373 (part). Lepldo- 

 jdeurus tetiuisculptus CPU., P. Z. S. 1865, p. 275. 



A variety is paler, tinged with rufous at the jugum. 



