1903.] NATURAL SCIENCES OF PHILADELPHIA. 409 



rior lateral border bear only small, low, smooth papillae; from these 

 areas they gradually differentiate into several distinct forms. Lower 

 flat papillae with from 4 to 8 peripheral radiating spines occur chiefly 

 on the postero-lateral half ; a few especially large examples of this type 

 which lie just behind the scar ridge may bear 1 or 2 apical spines in 

 addition to the peripheral ones. Smooth globular papillae without 

 spines are occasionally found with the latter. Along the scar ridge 

 are 1 to 3 (of which the mesial one is the largest and most character- 

 istic) very large papillae having the form of an irregular inverted cone, 

 the enlarged end of which is thickh' studded with rough processes. 

 On the entire area between the lateral end of the scar ridge and the 

 postero-lateral margin are numerous large, pale or colorless, erect, 

 clavate papillae with slender pedicels, and studded with peculiar rough 

 scaly nubs. A single marginal rank of similar but larger, recumbent 

 and usually brown papillae extends around the entire postero-internal 

 border. The papillae vary much in color; those on the ridge are gen- 

 erally yellowish-browm, the others varying shades of yellowish-gray, 

 gray with yellow spines, brown or nearly l^lack. The darkest are 

 usually found in a small group just mesiad of the scar ridge. The 1st 

 scale bears a central group of the large rough papillae and a complete 

 marginal circle of clavate ones, beneath which is a circle of short 

 cilia. The last has club-shaped papillae on its lateral margin only, 

 and nearly its internal half is free from cilia. 



When the scales are in place the entire animal presents a striking 

 superficial resemblance to a Chiton. The rough scale ridges con- 

 verge in each pair to form a series of \'s pointing forward. 



T}T3e, Sagami Bay, 3,700,63 fms.; Totomi Sea, 3.733, 49 fms.; 

 also one from an unknown station. 

 Lepidonotus branchiferus sp. nov. (PI. XXIII, figs. 7. 8, 9.) 



Outline short, broad, elliptical, very regular, somewhat depressed. 

 Length 26.5 mm., width to tips of setse 14 mm., to margins of scales 

 11 mm., depth 6 mm. 



Prostomium decidedly wider than long, its lateral margins wdth 

 prominent preocular protuberances, making this the broadest region; 

 eyes two pairs, rounded, black, the anterior much the larger and more 

 prominent, the posterior distant from them less than their own diam- 

 eter mesiad and caudad. Median tentacle with stout cjdindrical basal 

 piece slightly shorter than prostomium ; style about 4 times the length 

 of prostomium, tapering to a slender region beyond which is a subter- 

 minal ball and a short terminal filament. Lateral tentacles with 

 ceratophores less than ^ that of median tentacle, and continuous with 



