22 INVERTEBRATE ANIMALS. 



^ki^ Cab(c (Hase. 



The mark ^ indicates specimens or other illustrations exhibited in the Cases. 



Section SIPHONIDA. a-i^Mv, a tube. 



The presence of a well-developed respiratory siphon indicates, gener- 

 ally, that the species live more or less immersed in sand or mud. 



Group 61. — Family LUCINIDiE and allies. Lucina, 

 a name of Juno. Estimated number of species : recent, 

 362; British, 17; fossil, 330. From the Devonian 

 upwards. 



H Illustrations of the genera in the families Un- 

 guliniclfe, Laseida, Leptouidce, Galcommidce, 

 Solemyidce, AstartidcB. Fine series of Crassa- 

 tella. 



Group 62. — Family CHAMIDJj^ and allies, xa^w-a*, on the 

 ground. Estimated number of species : recent, 52 ; 

 British, ; fossil, 30. From the Chalk upwards. 



H Chama, Hippopus, Tridacna, Arcinella, Chame- 

 trachtsa, dc. Chama Lazarus, very fine. 



Upper Compartment. 



Small example of T. gigas, the largest known mol- 

 lusc ; the shell attains the weight of 500 lbs. 



Group 63.— Family CARDIID^ and allies. xap§/«, the 

 heart. Cockles. Estimated number of species : recent, 

 162 ; British 9 ; fossil, 300. From the Silurian 

 upwards. 



^ Cardium, Hemieardia, Bucardia, dc. 

 Adacna and Monodacna are generic forms from 

 the Caspian. 



Group 64.— Family CYRENID^ and allies. Cyrene, the 

 daughter of a river. The olive-green epidermis iiidi- 



