336 GASTEOCH,ENIDiE. 



Tube calcareous, claviform, free or fixed, often incom- 

 plete. 



Syn. Gastrochsena, Lam., not Bpengl. Trapezium, 

 Blainv. Quoyie, Desk. Eupellaria, Agass. Roxellaria, 

 Mke. 



Ex. R. dubia, Pennant, pi. 91, fig. 2. Shell, R. dubia, 

 2, a, 2, b. Tube, R. dubia, 2, c. 



The Gastrochcena modiolina of Lamarck, which we more 

 correctly term Rocellaria dubia, often forms flask-shaped 

 tubes, which are only attached by their neck to the fragments 

 of shells in which the animal burrows. It lines the crypts 

 which it excavates in shells and limestones with a shelly 

 layer. There are many species of Rocellaria, of world- 

 wide distribution, examples having reached us from the 

 East and West Indies, the British Islands, the Gallapagos, 

 Mauritius, Pacific Islands, and South America. 



Species of Rocellaria. 



apertissima, Desk. lamellosa, Desk. 



brevis, Sow. niacroschisma, Desh. 



cucullata, Desh. mytiloides, Lam. 



denticulata, Desh. ovata, Sow. 



difficilis, Desh. Philippinensis, Desh. 



dubia, Perm. plicatilis, Desh. 



hians, Chem. pupina, Desh. 



humilis, Desh. rostrata, Spengl. 



hyalina, Sow. rugulosa, Sow. 



impressa, Desh. Ruppellii, Desh. 



iudistiucta, Desh. spathulata, Desh. 



interrupta, Desh. tenera, Desh. 



intersecta, Desh. truncata, Sow. 

 laevigata, Desh. 



