ISCHNOCHITON. 77 



This is the only tropical species that I have met with, and it is 

 very abnormal in its stumpy projecting teeth, resembling those of 

 Tonicella. The girdle is, however, normal, the extremely minute 

 crowded granules presenting a somewhat bristly appearance under 

 the microscope. 



The above is taken from Carpenter's MS. The type specimen is 

 Mus. Cuming, No. 106. 



I. ASPERIOR Carpenter, n. sp. Unfigured. 



Shell small, oval, depressed, the jugum acute. Valves apicu- 

 late ; ashen, maculated with darker. Mucro rather raised, the 

 posterior slope concave. Entire surface under a lens seen to be 

 conspicuously pustulose ; central areas having about 7 subparallel 

 lines of small but projecting granules, bending toward the jugum, 

 closer on the jugal area. Lateral areas hardly elevated, having 

 about 3 very distant and a little larger lines of granules ; anterior 

 valve with about 18 such lines. 



Interior: anterior valve with 8, central valves 1, posterior valve 

 with 9 slits ; teeth acute, long ; eaves conspicuous, short ; sinus nar- 

 row, deep, laminated but scarcely dentate. Girdle thickly beset 

 with most minute purple smooth scales (and occasionally corneous 

 hairs, perhaps foreign to it). 



Length 11}, breadth 71 mill. ; div. 140. 



East Asia. 



f Trachydermon asperior CPE., MS. p. 19. 



The solitary specimen was found in a mixed group of species, 

 named C. pulcherrimus Sby., and Lept. craticulatus by Dr. Gould, 

 and coming from either Hong Kong or Hakodadi. It will be 

 easily recognized by its sculpture and minutely chaffy scales. 

 Whether it belongs to this genus or to Chcetopleura will probably 

 be decided by the gills. (Q?r.) 



I. PERORNATUS Carpenter, n. sp. Unfigured. 



Shell, small, subelongate, elevated; jugum acute; ashen or olive 

 maculated ; mucro slightly before the middle, planate. Central 

 areas with subparallel strong tuberculate bars, about 10 on each 

 side, interstices decussated ; jugal area granulate, sculptured in 

 front ; lateral areas strongly denned, having rounded irregularly 

 radiating tubercles, of which there are around the margin of the 

 posterior valve about 20, the median valves 5, anterior valve 24. 



