\ \N MUM III I I N 'I- -I'l.AX. 



Tlu- type ofM/r,/ /,,/,/ lln* is not .17. Ad. A' An-.. a> stated 



by Dall in IV - N /. Mus. 1*7*. p. 2W, but M. ;>///////* ( >r.. 



J81, p. 288. The first use of the nan 



unaccompanied 1>\ a diagnosis, will fall. At the time Carpenter 

 1 the Lrroup f'<>r M. j>hn<i> >/-, In- had never .seen the species 



A. 3P [081 8 II. Adam-. PI. 1. ti-s. i>:J. 24,25,26. 

 Shell elongated ; valves acutely heart-shaped, olivaceouB maculated 



with brown : . adi valve \\ith a wide, smooth dorsal ridge, the side 



unlove, the lateral area indicated by a raised line. 



(iirdle In-own, -pinulose; pores moderate sized, encircled by con- 



;la. 



Length 72, breadth 24 mill. .77. .; 



Tasmania, (Mus. Cuming) ; Flinders Island (Jos. Milligan.) 



Cryptoplax (Notoplax) speciosa H. A i> ., I'. Z. S. 1861, p. 385. 



This species re>embles A. ./y///.</V*/x I'ils. in the narrowness of the 



11 nt'thi- valves, but in typical specimens of that form 



iitum is decidedly narrower. In A. htnijihilll Pils. from 



la, which i- a X'>f< l/t l,ix in its apparently separated valves and 



ulate tail-plate, the tpeeiotiu ditli-rs in the longer, narrower 

 tegnx n tu in. 



I' my plat*- were drawn by Mr. E. A. Smith from the 



types. ( e following useful notes on the specimens 



in the British Museum : The lateral areas are distinctly marked 



y larger granules alonjr a rai-ed dia-onal line. The mucro of 



M)sterior valve is raised, at an angle of about 160, and situated 



at l: lOf third of the teirmentum. The jugular areas are 



smooth and rai>l : the scales of the sides are also smooth Hat 



and raised. The Birdie is entirely eovt red by a dense mass looking 



spongy, but consist iculi-s of moderate length and extremely 



There are conspicuous nores hut the hairs in them are 



not longer than the MM, and tin -n -f,.n- it i- dillicult to distinguish 



. The sinus is v- >v and d.-rp. Slits all very short. 



has grooves with raised edges extending from 



I 1 it rid \alve haviiiL' >i -ituated as in 



te il pr. ity regularly grooved 



radially, so as to < be margin, almost amounting to little nicks 



