﻿S AX IC AVA, 



Fl.\te II. 



Species 8. (Figs, a, b, c, d, Mus. Brit.) 

 Saxicava Australis. Sax. testa ohlongd, valde rugos'i, 

 plusminusve distortd ; wnbonibus maijnis, perclc- 

 vatis, fere terminalibus ; latere postico oblique pro- 

 ducto, angulato, ad angulum obsolete spinoso, 

 margine ventrali ad temiinmn sursuin acclieis, 

 margine terminali oblique Irimcato, margine dorsali 

 recti, ared complanald. 

 The Australian Saxicava. Shell oblon,?, very 

 rugose, more or less distorted ; uinboos large, 

 much elevated, nearly terminal ; posterior side 

 obliquely produced, angular, obsoletely spinose at 

 the angle, ventral margin sloped upwards at the 

 end, terminal margin obliijuely truncated, dorsal 

 margin straight with a flattened area. 

 Lamarck. Anim. sans Vert., v. p. 153. 

 Saxicava distorta, Say. 

 Mactra crassa, Peron. 

 Hab. Australia — (var.) United States. 



More tumid, especially towards the umbocs, than 

 Saxicava arctica. The younger specimens have spines 

 on the angle, as in that species, but these are worn off 

 as the shell becomes larger, leaving tubercles in their 

 places. The right valve is frequently deeper and 

 higher at the umboes than the left. The American 

 type (fig. (/) corresponds with the Australian and not 

 with the British form. 



Species 9. (Mus. Brit.) 

 Saxicava tf.ndis. Sax. testd rluimloided, elongat'i, 



tenui, subinflatd ; latere antico brevissimo, decliii ; 



wnbonibus elevatis, acutis,fere terminalibus ; latere 



postico suhattenuato, oblique acute angidato ; angulo 



subserrato. 

 The thin Saxicwa. Shell rhomboidal, elongated, 



thin, rather infiated ; anterior side very short, 



sloped ; umboes raised, sharp, nearly terminal ; 



posterior side rather attenuated, obliquely sharply 



angular ; angle a little serrated. 

 SowERiiV. Proc. Zool. Soc, 1834, p. 88. 

 Hab. ? 



Species 10. (Mus. Brit.) 



Saxicava GuEr.iNii. Sax. testa oblongd, angustd, 

 rertiHsculd ; latere antico brevi, oblique declivi, 

 infra subangulatd ; latere postico elongato, ad ter- 

 minum obtuse truncato; margine ventrali rectius- 

 culo, medio excavato. 



Guerin's Saxicava. Shell oblong, narrow, rather 

 straight ; anterior side short, obliquely sloped, a 

 little angidar below; posterior side elongated, 

 obtusely truncated at the end ; ventral margin 

 rather straight, excavated in the middle. 



Patraudeau. MoUusca. Plate I. 



llab. Mediterranean Sea. 



Species 11. (Mus. Brit.) 

 Saxicava Anoasii. Sax. testd irrcgulariter rhomboiJed, 

 magna, solidd, altd, svbinmqtiivalvi, valde inaqui- 

 hilerali, Jlavido-mbescenti, fusco nebulatd; valvd 

 dextrd cdtiilsculd, profundiord ; latere antico 

 brevissimo, declivi ; latere postico oblique angulato, 

 oblongo, ad terniiiium quadrato. 



Angas's Saxicava. Shell irregularly rhomboidal, 

 large, solid, elevated, rather inequivalve, very 

 inequilateral, reddish yellow clouded with brown ; 

 right valve rather the higher and deeper ; anterior 

 side very short, sloped ; posterior side obliquely 

 angular, oblong, square at the end. 



A. Adams. Proc. Zool. Soc, 1865, 643. 



Hab. St. Vincent's Gulf, S. Australia. 



The only species exhibiting anything like distinct 



colouring, excepting Saxicava purpurascens. 



Species 12. (Mus. Brit.) 

 Saxicava sriNiFEKA. Sax. testd pared, lavigatd, 

 svperne quadratd, infrd bilobeitd ; latere antico 

 brevissimo, wnbonibus terminalibus, margine ven- 

 trali profundi excavato ; latere postico lata, trun- 

 cato, margine dorsali et angulo obliquo decurrentibu^ 

 spinis acutis prominentibus ornatis. 



May, 1875. 



