ACANTlln. HI 



The ' .iv iin(|iir>ti<>n:ii)|r prOOift Of 



stock distinctly Aoonthockttoid in its orpmi/: 

 i-haraetrrs render it useful to tival that 

 elo-tdy allied, family. 



Vol. XIV, |>. \\xii, paragraph hft tor .-vnoj. 



Subfamily A< \M ii< im i 

 nisSPONGIOCHITON Carpenter. 

 See Vol. XIV, p. -0. This is probably u valid L r -iiu-, alii- 



At'inithni'hitf* but distinguished l>y tin- anterior dilation of tin.- gi 

 and the more regular slitting of the tail valve. 



Genus (?) LEPTOPLAX Carpenter. 



See Vol. XIV, page 25, where this genus was erroneously included 

 in the I#chnochitonincG. Specimens should be critically exam 

 now that it is placed next to Acanthochitea, for it may prove to be a 

 subgenus or section of the latter, near 



Genus ACANTHOCHITES Risso, 1826. 



Arauf/iochites, Acanthochcdes and Acanthochiton of authors, -f- 

 Phakellopleura Guild, (hand Shuttlw. !),-{- Phacellopl< / . M 

 <h'e/lus and Stectoplax of Carpenter,-}- Notoplax Ad., -\-Cryptom,, 

 (Blainv.) Guild. 



Valves partially buried in or covered by the girdle, the 

 part consisting of a smooth or striated dorsal band, and granu; 

 side-areas, the latter sometimes lacking. Anterior valve with ~) sym- 

 metrically placed slits ; median valves with 1 slit on each side ; pos- 

 terior valve with two or several slits. Girdle varying from d< : 

 hairy to naked, but always having four bristle-bearing pores around 

 the head valve, and a single series of pores on each side placed at 

 the sutures. Gills short, extending forward from one-third to t : 

 fourths the length of the foot. 



This gunus is distinguished from Leptoji/" S and 



Knlhnrina by the presence of bristle-bearing pores at the sutures, 

 and from the first two moreover by the less regular slitting of the 

 posterior valve. The u r i nii- l\<ithurin'i differs from .1 

 further in the more numerous, unsymuu-trical ant i in 



the gill-row, which is a- Ion;: as the t 



.['<mt lnn'h It*'* is the only ^eiius i of moiv than one species) in wl. 



