Report of the State Geologist. 



489 



Pattial SinvM8 cmd Genital Markin 

 Traces of these features are frequently retained on the shell 

 with more or less distinctness. The paUM smusea are usually 



Fig. 85.— Interior of brachial valve of Am- Fig. 86.— Eatonia pecuLiaria. The pallial 

 bocoeliaumbonata; showing the four adduc- sinuses on an internal cast of the pedicle- 

 tor scars valve. 



two convergent (Lingula, Oboltjs) or divergent (Strophomena, 

 Stropheodonta, etc.) trunks, from the outer margins of which 



Fig. 87- Ehynchonella acuminata., showing the pallial sinuses on an internal cast. A 

 pedicle- valve; B. umbonal view, a, adductor scars; b, diductors. (Woodward) 



emanates a series of secondary ramifying branches. Among the 

 Particulates there may also be branches along the inner margin 





Fig. 89.— Koninclin a Leonhardi; interior 

 of brachial valve, showing pallial sinuses 

 crossing the impressions of the spiral arms. 



CWOODWARD.) 



of these sinuses. In Strophomena, Stropheodonta, etc., the inner 

 margin of the main trunks bounds the genital area, which 

 1891. 62 41 



Fig. 88.— Rafinesquina expansa. Interior of 

 pedicle-valve, showing pallial sinuses. 

 (Davidson.) 



