74 



MALLEUS. ANOMIA. SPONDYLUS. 



Fig. 91. PECTEN JACOB^EUS. 



and Pediim, the shells of 

 what resembling the shell 

 of the Scallop in their gene- 

 ral form : 



11. The Hammer Oys- 

 ters Malle.vs (fig. 92) 

 which have a notch near 

 the hinge for the passage 

 of a byssus : the shell is 

 irregular and the ears are 

 prolonged, making its 

 shape slightly resemble a 

 hammer : the ANOMI^E, 

 in which the interior valve 

 is deeply notched (Jig. 93) 



lusks are not adherent, and can even 

 swim with considerable rapidity by 

 suddenly closing their valves. The 

 mouth is furnished wilh many 

 branched tentacula, which lake the 

 place of labial lamella?, and be- 

 tween the branchiae there is a small 

 oval foot. St. James' Pecten is 

 found on the coast of France. The 

 species of this genus are very nu- 

 merous and are very generally dif- 

 fused. 



The following genera are also 



placed among the oysters ; Lima 



which are oval or oblong and some- 



Fig. 93. ANOMfA. 



Fig. 92. MALLEUS. 



alongside of the ligament, permitting 

 the central part of the muscle to pass 

 through it to be inserted into a plate, 

 sometimes horny, sometimes stony, 

 by aid of which the animal attaches 

 itself: 



12. SPONDYLTJS, in which the 

 shell is foliated or even spiny, and 

 on each valve, at the hinge there 

 are two teeth which are received 

 into pits in the opposite valve: 



11. What are the characters of the genus Ma'lleus ? (Malleus, Latin, a 

 hammer.) What are the characters of the genus Ano'mia ? (Anomia ; 

 from the Greek, </, without, and womos, law ; because not easly placed accor- 

 ding" to the laws of classification.) 



12 How is the genus Spo'ndylus known ? (Spondylus, Latin, a spindle, 

 or shellfish.) 



