34 INTRODUCTION. 



Order CYCLOSTOMATA. 



Suborder I. ARTICULATA. 



Fam. Crisiidcs. 



,, II. TUBULATA. 



() Young stage. Stomatoporiform or Probosciniform. 

 Fam. 1. Tubuliporidce. Fam. 3. Idmoniida. 

 ,, 2. Entalophoridce. ,, 4. Horneridce. 



(b] Young stage. Cupuliform or discoid. 



Fam. 5. Fascigeridce. Fam. 7. Theonoidce. 



,, 6. Osculiporidce. 

 ,, III. DACTYLETHRATA. 



Reticuliporidce. Multiclausidce . Terebellariidce . 

 ,, IV. CANCELLATA. 



Discoporellidce. 



Order TEEPOSTOMATA. 

 Families represented in the Jurassic 



Fam. 1. Ceramoporidce. Chilopora. 



,, 2. Heterotrypida. Heteropora. 

 ,, 3. Amplexoporidce. Ceriopora. 



8. PREVIOUS WORK ON THE JURASSIC BRYOZOA. 



The study of the Jurassic Bryozoa is facilitated by the fact that 

 this group was practically unrecognized in the first half-century of 

 the study of systematic zoology. The first work which contains any 

 information of much importance upon this subject is Lamouroux's 

 "Exposition Methodique des Polypiers," published in 1821. In 

 this were figured specimens of most of the common forms found in 

 the Bathonian deposits of Normandy ; they were fairly well figured 

 and described, and no less than nine Jurassic genera date from this 

 work. These names gained general acceptance by zoologists, who 

 unfortunately have used some of them in a sense different from that 

 in which they were proposed by Lamouroux. Thus, Idmonea is 

 generally said to be "erect" in zoological diagnoses; whereas the 

 type species is encrusting. Milne Edwards (1838) and Michelin 

 (1840-6) added some new species to those described by 

 Lamouroux, and D'Orbigny, both in his Prodrome and the "Pale- 

 ontologie franchise" (1850-2), named many new forms; but he 

 gave such imperfect diagnoses that most of them are indeter- 

 minable. In 1854 appeared the monograph of Ed. Haime, which 

 is the most valuable work published upon this group. He 

 accurately figured and described most of the principal forms, all 



