516 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.55. 



tract pustulose; interior whitish with small narrow straight-edged 

 jugal sinr.s, and rather wide arcuate siitiiral laminae; intermediate 

 valves with the first axially wider than the rest, the jugal area wide, 

 axially sculptured with interrupted axial threads or rows of 

 elongated pustules, the lateral areas ill defined, with only very few 

 irregularly scattered prominent pustules, more abundant in some 

 specimens; internally whitish or pale greenish; the jugal sinus nar- 

 row, the margin in all the valves projecting tongue-like; the sutural 

 laminae arcuate. Length, 16; width, 8; height, 4 mm. 



Habitat. — Angeles Bay, Gulf of California, W. J. Fisher. Cat. 

 No. 110345, U.S.N.M. 



This belongs to the same group as T. fustulifera., to which it is 

 nearly allied but separated by sufficient characters. The projection 

 of the margin of the jugal sinus is most prominent in the seventh 

 valve, but is found in all the intermediate valves. The inner surface 

 of this feature is smooth. The coating of the girdle is less leathery 

 than in the more southern Tonicias, but under the microscope even 

 they show minute spinules more or less abundant. 



TONICIA PUSTULIFERA, new species. 



Chiton of moderate size, polished, yellowish mottled with dark 

 green, dark brown and brown dots, the back rounded, the girdle yel- 

 lovv'ish, densely covered with minute short spinules giving a velvety 

 aspect and with no fringe of longer spines at the border; anterior 

 valve with 8, posterior with 11, intermediate valves with single slits, 

 the insertion plates minutely radiallj'^ striated; anterior valve more 

 than semicircular with a profusion of minute pustules corresponding 

 to sense organs and leaving a puncture when worn off; otherwise 

 smooth ; posterior valve smaller with the mucro much in front of the 

 center, the central area narrow, sculpture as in the anterior valve, 

 internally with a pink spot, the jugal sinus small and shallow, the 

 sutural laminae long and narrow ; intermediate valves with the first 

 axially longer than the others, the valves slightly mucronate, the 

 jugal area narrow and smooth except on the first valve which has a 

 few axial grooves, the pleural tracts smooth except for a few very 

 feeble wavy subaxial threads often obsolete on one side of the same 

 valve, stronger near the jugum and on the posterior valves, and a few 

 scattered very minute pustules; there are faint traces in spots, of a 

 microscopic decussation ; lateral areas without ribs, feebly indicated, 

 bearing oblique rows of minute pustules; internally white, pinkish 

 under the jugum, the jugal sinus narrow, deep, straight edged, the 

 sutural laminae broad, arcuate ; the gill rows ambient. Length about 

 19; width, 10; height, 5 mm. 



Habitat.— San Pedro, California. Cat. No. 218736, U.S.N.M. 



