52 On ChilosfomafoHS Characters in Fossil Bryozoa. 



Royaii, near Bordeaux ; but it would seem that he had more 

 than one species before him, as the avicularia figured are not 

 all the same, Those, however, that I collected in Royan have 

 an avicularium differing from any figured by d'Orbigny, and 

 therefore it seems necessary to describe it as a new species 

 for the purpose of identification. 



The avicularia sometimes occur in transverse rows, at other 

 times irregularly distributed. The proximal portion of the 

 avicularium has a plate, which is but slightly depressed ; the 

 distal end is much more depressed, with an opening at the 

 lower part and a median slit j tlie end of the beak is raised. 

 The closures referred to seem to be constant in shape, starting 

 from tlie base'and two sides, joining in the middle ; but some- 

 times they start from four points. The contraction below 

 the aperture is described on page 49. 



A genus Multinodelea was created by d'Orbigny for a form 

 consisting of more than one layer ; but I found many speci- 

 mens, some with and some without superimposed layers, 

 and quite agree with Pergens that Elea and Bodelea must be 

 placed in one genus. One section shows four superimposed 

 layers, and it is very curious to see how these layers grow, 

 for here (see fig. 4) the aperture is closed by a plate, and 

 from this one wall of the tube forming the fresh zooecium 

 grows. As to the meaning of this extraordinary origin of 

 the new zooecia I would not attempt an explanation. 



Melicertites semiclausa, d'Orb. 

 (PI. VI. figs. 1 and 8.) 



Melicertites semiclausa, d'Orb., Pal. Fr. p. G19, pi. 618. figs. 6-10, 

 pi. 7^6. fig. 16. 



This species was described by d'Orbigny from Le Mans as 

 having no " cellules accessoires ; " and if he had seen the 

 avicularia it would have been placed with Nodelea, showing 

 how artificial the division was. In my specimen from Le 

 Mans the beak of the avicularium is large and expanded at 

 the end, sometimes unsymmetrically so. The front wall of 

 the zooecia has large pores. 



Although calling attention to various points of structure, I 

 am not able to fix the limits of the Melicertitidse ; nor is the 

 object of the communication to pronounce an opinion as to 

 whether all the fossils described by Mr. Ulrich are Bryozoa, 

 or whether some of the forms may not have to be removed 

 from or to Cryptostomata ; but there can be no doubt that 



