SPINNING MOLLUSCS. 307 



to hang suspended, and that the threads are sometimes of con- 

 siderable length. Chondropoma dentatum* (Key West), a shell 

 about half an inch long, is stated by Binney to spin a short 

 thread, and hang suspended by it during rest ; and at the end of 

 one of his chapters the author gives a small woodcut, which, 

 though not described, evidently represents this shell, slightly 

 enlarged, hanging by a short thread from a leaf-stalk ; the thread, 

 according to the drawing, proceeds from between the operculum 

 and the outer lip of the shell, considerably nearer to the umbilicus 

 than to the suture. (Fig. 5.)t 



Another species, Chondropoma plicatalum, a little larger than 

 the last, was obtained by Dr. J. S. Gibbons, at Puerto Cabello, 

 hanging suspended during repose by a thread j-J in. long, very 

 thin, but strong, flexible, and silk-like ; the thread issued from 

 between the operculum and the outer lip, two-thirds of the 

 latter's length from the suture, a position similar to that shown 

 in Binney's drawing. I Similar suspension was observed by 

 Dr. Gibbons also in the allied Tudora megacheila. Near St. 

 Ann's, Curasao, on a waste piece of ground which appears to 

 have been a kind of conchologist's paradise, he found this 

 creature in great abundance, " suspended by its silk-like thread 

 from Acacia boughs, or strewed thickly along the ground under- 

 neath " ; the thread resembled that of Chondropoma plicatulum, 

 but was shorter.§ 



Among Old- World Cyclostomas, we have a note relating to 

 Cyclostoma articulatum, a shell of considerable size, belonging to 

 Kodriguez (Mascarene Islands) : — " When it retired and closed 

 its shell," says Woodward of a specimen kept under a bell-glass, 

 11 it still adhered, and sometimes became suspended, by a 



* Cyclostoma dentatum. 



f Binney, ' Terrestrial Air-breathing Mollusks of the United States,' ii. 

 (1851), pp. 347-9 ; and see also W. G. Binney, ' Land and Freshwater Shells 

 of North America,' 1865, pp. 96-7, fig. 194 (Smithsonian Miscellaneous Col- 

 lections, vii.) ; and Tryon, 'American Journal of Conchology,' iv. (1868), 

 p. 11 ; pi. xviii. fig. 15. 



I Gibbons, ' Journal of Conchology.' ii. (1879), p. 134 ; and in Tye, 

 ' Quarterly Journal of Conchology,' i. (1878), p. 412. 



§ Gibbons, ' Quarterly Journal of Conchology,' i. (1878), pp. 411-2 ; and 

 Tye, I.e. 



y 2 



