﻿SOLKNATA 461 



black, scarcely shining ; hinge with a low ridge in each valve 

 in place of laterals; pseudocardinals wanting; nacre bluish- 

 white, dirty, having a posterior sinus distinctly marked out. 

 Length 127, height 34, diam. 18 mm. 



China. 

 Mycctopus iridineiis Hkudh, Jl. de Conch., XXII, 1874, p. 117; 



Conch. Fluv. Nank., I, 1875, pi. vm, fig- I9- 

 Solenaia iridinea Simpson, Syn., 1900, p. 657. 

 Mycetopus similis Hkude, Conch. Fluv. Nank., Ill, 1877, pi. 



xxiii, fig. 50. 



A smaller species than 5. oleivora, rather more arcuate, 

 narrower proportionally in front and having much darker 

 epidermis. It is smaller than sole nifo mils, has a more decided 

 and angled posterior ridge, has no radiating sulcus on the 

 posterior slope and the nacre is differently colored. 



Solenaia rivularis (Heude). 



Shell somewhat elongated, very much widened behind, m- 

 equilateral, very slightly arcuate, compressed ; posterior ridge 

 rather sharply angled ; beaks apparently low and placed at a 

 considerable distance from the anterior end; posterior end 

 subtruncate, the truncation below meeting the base line at an 

 acute angle; on the posterior slope there is a slight, radial 

 ridge; surface apparently slightly sulcate, the anterior end 

 having stronger sculpture; epidermis olivaceous; nacre rose, 

 spotted. 



Length 65, height 28, diam. 20 mm. 



China. 

 Mycetopus rk'ulans Hkudk, Conch. Fluv. Nank.. IIT, 1877, 



pi. XXIII, fig. 49- 

 Solenaia rivularis Simpson. Syn.. 1900. p. 657. 



The dorsal and ventral lines are very slightly curved so 

 that the shell is a trifle arcuate. The posterior end is very 

 much widened ; it is subtruncate and faintly biangulate behind. 

 It is shorter in proportion than soleniformis or oleivora. 



