BULLETIN 37, UNITED STATES NATIONAL MUSEUM. 



SKETCH OF GENERAL ARRANGEMENT. 



A. CLASS BRACHIOPODA. 



I. Order Artbropomata. 



II. Order Lyopomata. 



B.-CLASS PELECYPODA. 



I. Order Prionodesmacea. 



1. Suborder Ostracea. 



2. Snborder Anomiacea. 



3. Suborder Pectin acea. 



4. Suborder Mytilacea. 

 [5. Suborder Naiadacea. 



6. Suborder Trigoniacea]. 



7. Suborder Arcacea. 



8. Suborder Nuculacea. 



9. Suborder Solenornyacea. 

 Order Teleodesmacea. 



1. Suborder Carditacea. 



2. Suborder Leptonacea? 



II 



II. Order Teleodesmacea Continued. 



3. Suborder Lucinacea. 



4. Suborder Chamacea. 



5. Suborder Cardiacea. 



6. Suborder Veneracea. 



7. Suborder Tellinacea. 



8. Suborder Mactracea. 



III. Order Anomalodesraacea. 



1. Suborder Anatinacea. 



2. Suborder Myacea. 



3. Suborder Solenacea ? 



4. Su'iorder Ensiphouacea. 



5. Suborder Adesmacea. 



C. CLASS SCAPHOPODA 

 I. Order Solenocouchia. 



D. CLASS GASTROPODA. 

 aa. SUBCLASS ANISOPLEUKA. 



I. Order Pteropoda. 



1. Suborder Thecosomata. 

 2 Suborder Gymnosomata. 



II. Order Opistbobraucbiata. 



1. Suborder Tectibranchiata. 



A. Superorder Euthyneura. 



[III. Order Nudibrancbiata.] 

 IV. Order Pulmonata. 



t. Suborder Stylommatophora. 

 2. Suborder Basommatophora. 



B. Superorder 

 I. Order Ctenobrancbiata. 



1. Suborder Orthodonta. 



a. Superfaniily Toxoglossa. 

 6. Superfamily Rhacbiglossa. 



2. Suborder Streptodonta. 



o. Superfamily Ptenoglossa. 

 6. Superfamily Gymnoglossa. 



Streptoneura. 



I. Order Ctenobrancbiata Continued. 

 2. Suborder Streptodonta Cont'd. 



c. Superfamily Taenioglossa. 



d. Superfamily Docoglossa. 



e. Superfamily Rbiphidoglossa. 

 /. Superfamily Zygobrancbia. 



bb. SUBCLASS ISOPLEURA. 

 C. Superorder Folyconcltce. 



I. Order Polyplacophora. 



a. f uperfamily Eocbitonia. 



b. Superfamily Opsicbitonia. 



E. CLASS CEPHALOPODA. 

 I. Order Dibranchiata. 



1. Suborder Oetopoda. 



2. Suborder Sepiopbora. 



NOTE. The reader will understand that this sketch does not pretend to complete- 

 ness, except for the following tables. 



