1881.] MOLLUSCA OF 'LIGHTNING* ETC. EXPEDITIONS. 693 



and from the mouth b}' the small valvular opening referred to, and 

 having its sides supported behind by tlie expanded hyoid bones, 

 constitutes a most perfect exhauster ; while tbe broad epiglottis, 

 permanently folded over the larynx in front so that its aperture is 

 directed upwards towards the spine, and the great size of the fibro- 

 cartilaginous masses extending forwards from the arytenoid cartilages 

 to the epiglottis (fig. 5, c, p. 690), effectually guard the glottis, 

 preventing any part of the food, such as the small fig-seeds, from 

 being drawn into the air-passages. 



In the males of E. monsirosus, fratiqueti, comptus, and pusillus, 

 permanent inflation of the pharyngeal sacs is rendered possible by 

 the manner in which, as above described, the nasal and oral cavities 

 are capable of being completely shut off from the pharynx. Con- 

 sidering the large size and position of the apertures by which tliese 

 sacs communicate with the pharynx, it would appear at first sight 

 that most of the food entering the pharynx must find its way into 

 them. This ditficulty is removed if we allow that suction by means 

 of the inspiratory action of the lungs has any thing to do with 

 drawing the semifluid food into the pharynx ; for it is evident that 

 the same action would cause the walls of the sacs to collapse inwards 

 upon the apertures, and so close tlieir communication with the 

 pharynx at the very time when it was most needed. 



5. On the Mollusca procured duriug the ' Lightning ' and 

 ' Porcupine ' Expeditious, 1868-70. (Part III. i) By 

 J. GwYN Jeffreys, LL.D., F.R.S., F.Z.S. 



[EeceiTed May 20, 1881.] 

 (Plate LXI.) 



CONCHIFERA (continued). 



Family VIII. Kelliid^. 



I. Pythina SETOSA, Duulcer. 



^ Coralliophaga setosa (Dunker), Grube, Die Insel Lussin und ihre 

 Meeresfauna, 1864, p. 48. 



Scintilla recondita, Fischer, Les Fonds de la Mer, 1872. p. 49, 

 pi. ii. f. 3. 'V > 



'Porcupine ' Exp. 1870 : Atl. St. Tangier Bay ; Med. 50, 50a. 



Distribution. Arcachon to Mogador, Sicily, and Adriatic. Depths 

 5 to 86 fathoms. 



Fossil. Pliocene : Monte Mario and Ficarazzi. 



Sportella caillati, Conti, and Kellia macandrewi, Fischer. It be- 

 longs to Pythina in respect of the hinge as well as of the peculiar 

 divaricating sculpture, 



' For Part I. see P. Z. S. 1878, p. 393 ; for Part II. see P. Z. S. 1879, p. 553. 



