CONCHIFERA. 



757 



Gastrochcena SPENGLER (Fistulana BRUG., LAM., and Gastro- 

 clicena LAM.). Shell thin, equivalve, gaping at both ends, with 

 hinge linear edentulous, and ligament external elongate. Calca- 

 reous tube clavate, including the bivalve shell. Mantle with a 

 small aperture for the passage of a short foot, furnished with a 

 small byssus. Two tracheae coalesced, long, very contractile. 



Sp. Gastrochcena mumia SPENGL., Fistulana clava LAM., SPENGL. Skrivter 

 af Naturh. Selskab. n. i, PI. 2, fig. i, BLAINV. Malac. PI. 81, %. 3; on 

 the coast of Coromandel ; the tube is free, and grains of sand often adhere 

 to it. Other species, still, live enclosed in holes of madrepores and other 

 stony polyparies ; in these the calcareous tube was seen above the head, 

 and they were separated from the preceding as a distinct genus (Gastro- 

 chcena LAM.). [The name Chccna substituted for Gastrochcena by A. J. 

 KETZIUS (Nova Testaceor. Genera, Diss. def. a L. MUENTER PHILLIPSON, 

 Lundse, 1788, p. 19), although adopted by SPENGLEB, has found no favour.] 



Clavagella LAM. Sheath tubular, calcareous, free or enclosed 

 in other marine bodies, clavate, and often covered with spines, or 

 terminated by a cloven disc or calcareous branched tubes. One 

 valve fixed in the wall of tube, the other free, contained in the 

 cavity of tube. 



Most of the species of this genus are fossil, and occur in tertiary forma- 

 tions, as Clavagella echinata LAM., Ann. du Mus. XII. PI. 43, fig. 9, Clav. 

 baccillaris DESH. Conchyl. PI. I. figs. 4 10. A recent species is Clav. 

 aperta Sow., Cuv. R. Ani., ed. ill., Moll. PL 117, fig. 2, from the Mediter., 

 also Clavag. lota BKOD., of which the animal was described and the anatomy 

 given by OWEN; see W. J. BfiODERiP and R. OWEN in Transact, of the 

 Zool. Soc. i. 3, 1835, pp. 261 271, PI. 35, figs, i 8, PI. 30, figs. 8 16. 



Aspergillum LAM., Penicillus BRUG., Arytene OWEN. Bivalve 

 shell incrusted in the wall of calcareous tube. Tube cylindrico- 

 clavate, open at the narrow part, at the opposite end closed by a 

 disc supplied with numerous tubular foramina and a central fissure. 



Sp. Aspergillum Javanutn LAM., Serpula penis L., HUMPH. Anib. Rariteitk. 

 PL 41, fig. 7, BLAINV. Malac. PL 81, fig. 2; from the Indian Sea; 

 Aspergillum vaginiferum LAM., Arytene vaginifera LEUCK., EUEPPELL Atl. 

 zu der Reise im nord. Afrika, wirbellose Thiere, 1828, Tab. xn. ; in the Red 

 Sea. These animals live in the sand of level beaches and banks, and fix 

 themselves in it with the broad end of the tube. The animal, which is 

 club-shaped, became first known through RUEPPELL'S Travel*. 



