466 SUPPLEMENT. 



them, as tlie Bryozoa move their oral tentacles ; but in no instance were the 

 arms extended, When the Crania opetied^ the upper valve turned upon its 

 hiuge-line. (Barrett, An. Nat. Hist.) 



The anatomy of Terehratula and Rhynchonella has been further investi- 

 gated by Dr. Gratiolet, ]\Tr. Huxley, and Mr. A. Hancock. 



The pallial arteries (mentioned p. 212, and figured p. 227, fig. 141) are 

 regarded as " narrow bands from which the ovaria or testes are developed." 

 The nature of the organs previously described as hearts is rendered doubt- 

 ful, as they appear to open externally, forming the "ovarian orifices" of 

 Hancock; the plaited organs (/^, h, fig. 165), described as auricles, are com- 

 pared \\^th nidamental glands. 



UhynchoTiella has two additional "hearts" above the others, one on each 

 side of the liver. The peculiarity of the ovarian spaces in Rhynchonella 

 and Orthis (described at p. 212, and represented in figs. 139, 140, 145, 147 

 letter o) is explained by the structure of the ovarian sinuses in the recent 

 Rhynchonella ; "the floor of this great sinus is marked out into meshes by 

 the reticulated genital band, and from the centre of each mesh a flat band 

 passes, uniting the two walls of the sinus, and breaking it up into irre- 

 gular partial channels." The insertion of these bands produces the punc- 

 tures in the shells represented in the figures above referred to. The 

 membranes which support the alimentary canal are described, and explain 

 the origin and nature of the septa in String ocephalus aud Pentamerus.. 

 The mode of termination of the alimentary canal is not yet satisfactorily 

 made out. 



Prof. Oscar Schmidt has observed the existence of flattened and radiated 

 calcarious particles in the mantle, arms, and cirri of Terebratulina caput- 

 serpentis ; their occurrence appears to be very general in the Brachiopoda^ 

 and accounts for the frequent preservation of internal structures in fossil 

 specimens. 



Dr. Gratiolet has pointed out that the true function of the cardinal mus- 

 cles of Terebratula was known to Prof. Quenstedt, and published by him in 

 1835. (Wiegm. Archiv. II. 220.) 



SuESSiA (imbricata) Eugene Deslongchamps, 1855. (Dedicated to M. 

 Suess.) Shell like Spirifera; textm-e fibrous; hinge area wide as the shell ; 

 foramen deltoid ; large valve with two cardinal septa, and a prominent cen- 

 tral septum, supporting a little plate; small valve with a tri-lobed cardinal 

 process, and a broad 4-partite hinge plate, with processes from the outer 

 angles of the dental sockets ; crura of the spires united by a transverse band 

 supporting a small process. Fossil. 2 sp. U. Lias, Normandy. 



Davidsonia, p. 232. The upper valve sometimes exhibits markings 

 derived from the surface on which the shell has grown. 



Zellania (Davidsoni) Moore, 1855. {Ety^n. Zella, a lady's name?) 

 Shell minute, orthi-form ; texture fibrous ; hinge area short, foramen angu- 



