Notes on the Collection 79 



callizona, Pils. and C. exoptandus, Bednall. There are 

 also specimens of Katharina, Tonicia, Mopalia, Isch- 

 nochiton, Cryptochiton, etc. 



4. SCAPHOPODA. This circumscribed little 

 group is represented by ten species of Dentalium, and 

 the exceedingly rare Siphonodentalium quinquangulare 9 

 Forbes, from a depth of 1793 feet in the Mediterranean 

 Sea, illustrating the two known families of "tooth shells" 

 (Dentaliidae and Siphonodentaliidae). 



5. PELECYPODA. A good collection of bivalves 

 is rare, and the comparative absence of descriptive 

 works on pelecypods has discouraged many whom the 

 beauty or oddity of these shells would attract. This 

 very absence of literature makes a large, authentically 

 named collection of bivalves of the greater value to the 

 student. 



It is as much a treat to examine here the specimens 

 of Veneridae as of Cypraeidae, Spondylidae as Volutidae, 

 Pectinidae as Muricidae, and the bivalves become very 

 much worth while, as indeed they should be. It is 

 through no lack of merit that these forms receive less 

 attention than the univalves. They have their proper 

 place in this collection with full rank and dignity. 



First come the remarkably modified burrowing 

 types of the families Pholadidae and Gastrochaeni- 

 dae, specimens of Penitella concamerata, ensconced in 

 solid rock, prisoners in domiciles of their own construe- 



