CLAVAGELLA, a genus of Teataceous Acephalous established by Lamarck in the fifth volume of the Histoire Naturelle des Animaux sans Vertebres,' published in 1818, and arranged by him under his Tubicoldes, between Aspergillum and Fist ulana. He described four species, all fossil, referring at the same time to the Annales du Mns6tun,' where he had figured the first of them under the name of Fiztulana echinata. Lamarck thus defines the genus A tubular shelly sheath, attenuated and open riorly, terminated posteriorly in an ovate subcompressed club beset with tubular spines ; the club presenting on one side the one valve fixed in its wall or substance, while the other valve remains free in the tube!' The genus was only known in a fossil state to conchologists, when Mr. George Sowerby observed in the British Museum a recent speci men, which he at first thought might be an Aspergillum, inclosed in a mass of stone. On application to Mr. Children, that gentleman allowed Mr. "Sowerby to examine it more closely, and on scraping away some of the investing stone the latter found Claragella aperta, the first recorded recent species, and figured and described it in his Genera of Recent and Fossil Shells.' The same naturalist, on the return of Mr. Samuel Stutehbury from his voyage to some of the Australian and Polynesian Islands, described and figured (1827) a second species, Claragella enemas, three specimens of which were with difficulty obtained by Mr. Stutchbury at North Harbour, Port Jackson, in a siliceosis grit like that of the coal-measures, where their presence was betrayed just beneath low-water mark, by their forcible ejection of the water from the aperture of their tubes: the specimen of Claragella australis figured by Mr. Sowerby is also in the British Museum. In 1829 Mr. Henry Stutehbury, in arranging the collection of Mr. Isaac Lyon Goldsmid, suspected the presence of a Clavegella in a mass of Astrawora, and, on fracturing the specimen, laid open two individuals of another species, Claragella elongata, Broderip. According to Curler, and a notice in the Annales des Sciences Naturelles' (tome xvii., p. 78). M. Audouin (1829) described a recent species, and 31. Rang, in his Manuel des Mollusques' (1829), mentions another, apparently Claragella rapa.
Still the animal remained unknown ; when, on the return of Mr. Cuming from his first voyage, that zealous collector produced another specimen which fortunately included the soft parts. A fragment of calcareous grit was dredged up by Mr. Cuming from a depth of eleven fathoms, at the island of Muerte, in the Bay of Guayaquil, and in this was the greater portion of the chamber and tube, both valves, and the animal of Claragella lata of Broderip. Mr. Broderip, who has described this
and two other recent species in the first volume of the Transactions of the Zoological Society' (p. 261), says, that a close examination of the recent species has convinced him that though one valve is always fixed or imbedded in the chamber, and soldered, as it were, to the tube, so as to make one surface with it, the tube is not necessarily continued into a complete testaceous clavate shape. In Mr. Goldsmid's best and largest specimen, the fixed valve was imbedded in the coral, and though continued on to the tube or aiphonie sheath, was sur rounded by the wall of the coral chamber at its anterior extremity. In the other specimen the fixed valve was also continued on to the tube. In the firat-mentioned specimen of Claragella elongata, at the anterior or greater end of the ovate chamber, an insulated or shelly plate had been secreted with tubular perforations ; that part of the chamber having afforded (apparently at a former period) the best communication with the ambient fluid : but a calcareous deposit having almost entirely cut off that communication, the animal seemed to have been compelled to secrete a second shelly plate towards the anterior ventral edge of the fixed valve, where the perforation of some other shell (a Lithodomus probably) secured the necessary influx of water. Nor is this the only instance of the secretion of a second tubular plate which has fallen under Mr. Broderip's notice. In the last-mentioned or smaller specimen, the perforated shelly plate joins the anterior ventral edge of the fixed valve laterally, that point of the chamber being evidently the most practicable for communicating with the water by means of the tubules : the rest of the anterior edge of the fixed valve is surrounded by the coral wall. In Mr. Cuming's specimen the fixed valve is continued on to the tube. The anterior edge of this valve is surrounded by the naked wall of the chamber, and the greater end of the chamber, or that part of it which is oppo site to this anterior edge, being impracticable, from its thickness, as a water communication (with a small exception, which, not improbably, had ceased to be available), the auimal had been driven to secrete the perforated shelly plates not far from the throat of the tube on either side, where the chambers of Petricolce or Lithodona opened a passage to the surrounding water.