78 PROCEEDINGS OF THE ACADEMY OP [1894. 



longer than the harsh, stiff pile of the 

 girdle generally ........ Coxi 



ee. Posterior margin of insertion- plate of valve 



viii biaugular; sides of valves with flat or 



concave pustules; tufts noticeably longer 



than the pile of the girdle. 



/. Dorsal areas smooth, with delicate 



longitudinal striie . . grariostriatus 



ff. Dorsal areas strongly, deeply striated 



longitudinally BednaUl 



cc. Valve viii with more than two slits. 



d. Tegmentum of valve viii pear-shaped, longer 

 than wide; sides of valves pustulose, dorsal 

 area defined, smooth; tufts subobsolete, speciostis 

 dd. — Tegmentum of valve viii irregularly rounded ; 

 pleural tracts of valves longitudinally costate, 

 lateral areas granulated; dorsal areas deli- 

 cately striate longitudinally . . . Matthewsl 



Acanthocliites (Loboplax) costatus Adams and Angas. Man. of Concli., XV, p. 

 40, PI. 3, lig. 74. 



This species is distinguished by its strongly lobed head valve from 

 all other known Australian Acunthochites. It is allied to A. viola- 

 ceiis of New Zealand and A. tridaciia of New Caledonia. A. costa- 

 tus has been collected by Angas at Watson's Bay, during an un- 

 usually low tide ; also by Coppinger in Port Jackson. It has not 

 been found there by Dr. Cox. 



Acanthochites (Meturoplax) retrojectus^ PilsLry. PI. II, figs. 13, 13, 14, 15. 

 Nautilus, vii, p. 107, January, 1894 (Preliminary description). 



Shell small, narrow and elongated, convex, not carinated, Ijlack 

 or black-brown, with a whitish "V" or three white stripes on each 

 valve, sometimes broadly maculated with whitish at the sides, some- 

 times unicolored dark chestnut brown. Intermediate valves moder- 

 ately l)eaked, convex behind (except valve ii, the posterior margin of 

 which is straight), sculptured with comparatively coarse, rounded, scat- 

 tered pustules, which become smaller and more crowded toward the mid- 

 dle, and are lower and less distinct on the ridge; no areas being dis- 

 tinctly differentiated on the valves. End valves similarly sculptured. 



* In allusion to the backward thrown mucro. 



