SCIENCE. 



[N. S. Vol. XV. No. 36P. 



structure, closed and tapering to a rela- 

 tively small point of attachment below, 

 nearly filled with a vesicular mass of shell 

 laminfE internally, preserving a smooth- 

 walled body cavity with a reflexed margin 

 at the upper end, without any trace of sub- 

 division in the walls, or dentiform proc- 

 esses. He pointed out some similarities 

 in the form of the aperture to the sessile 

 barnacles {Balanus) from which animals 

 the undivided tube structure seemed to 

 definitely separate the new organism. Sub- 

 sequently he described an imperfect speci- 

 men as a Balanus (B. estrellanus Conrad, 

 1857), but still later (1864) he referred it 

 to Radiolites, in the course of some rectifi- 

 cations of his earlier papers, and stated 

 that it was characteristic of the Cretaceous 

 of California. 



In 1866 Gabb stated ('Pal. Cal.,' II., p. 

 62) that it was a fossil of 'the Bituminous 

 shale, the best marked member of our Up- 

 per Miocene,' and referred it to the Hip- 

 puritidffi, an opinion provisionally accepted 

 by Stoliczka in 1871,* notwithstanding the 

 fact that the upper valve was unknown and 

 the supposed lower valve showed no traces 

 of muscular impressions, pallial line or 

 tooth sockets. Tyron,f in 1884, copies 

 Gabb's remarks without comment. ZittelJ 

 and Barrois, in 1887, regarded it as a prob- 

 lematical organism possibly referable to the 

 corals, while in the same year Fischer ex- 

 presses the opinion§ that it is more like a 

 large barnacle than a Ilippurite. Most of 

 the manuals and check-lists prudently omit 

 all reference to it. 



During the past season Mr. Homer Ham- 

 lin of Los Angeles sent to the writer a 

 collection of fossils from southern Califor- 

 nia containing numerous Miocene types, 



*' Cretaceous Peleeypoda of India,' p. 239. 

 t' Structural and Systematic Conch.,' III., p. 

 206. 



t'Traite de Pal.,' II., p. 86. 

 §'Man. de Concliyl.,' p. 1064. 



including Lyropecten magnolia and L. 

 Heermanni Conrad, from a horizon of 

 which the matrix is a cemented calcareous 

 gravel (not the bituminous shale), contain- 

 ing several examples of Tamiosoma; not 

 only the gregai-ious colonies, such as were 

 described by Conrad, but also solitary in- 

 dividuals and certain flat saucer-like, con- 

 centric valves with reflected edges, which 

 were naturally taken to be the long-sought 

 upper valves. One solitary individual ap- 

 peared to have this flat valve in situ and a 

 sagittal section of it was made, to study 

 the relations of the body cavity. It may be 

 mentioned in passing that all the material 

 in the beds from which these fossils came 

 has been more or less crushed so that per- 

 fect specimens are extremely rare. 



The result of the sectionizing was most 

 unexpected. There was no body cavity and 

 the flat saucer-like portion proved to be 

 merely the basal portion of the tube, which 

 in solitary individuals starts from an ex- 

 tremely small point of attachment to some 

 object and grows concentrically in a flat 

 form until it is an inch or two in diameter, 

 after which it changes its manner of 

 growth and rises in columnar fashion. In 

 the gregarious groups the growth forms an 

 inverted cone, owing to the mechanical 

 difficulties in the way of lateral expansion. 

 A section of the shelly matter showed that 

 it is entirely destitute of the prismatic layer 

 of the RippuritidcB, and that the structiire 

 of the shell is precisely that of the sessile 

 cirripedes. Since the tube is entire and not 

 divided into valves, and is quite destitute of 

 any radial structure, it was evident that 

 the organism is not homologous with the 

 valvular case of the sessile barnacles, which 

 is always divided into plates more or less 

 distinctly fused with one another, and that 

 it cannot be a coral. 



The only remaining alternative then ap- 

 pears to be that the fossil described by 

 Conrad is homologous, not with the valvu- 



