472 J. H. ORTON. 



XIII. THE MODE OF FEEDING IN THE ALLIES OF 



CKEPIDULA. 



The nearest allies of Crepidula doubtless all feed as Crepidula itself 

 does. Such a deduction may fairly be drawn at once from the simi- 

 larity in the mode of life of those animals and the general similarity 

 of their organs in the region of the mantle cavity. I have examined 

 Calyptraca chinensis alive, and find that it feeds in exactly the same way 

 as does Crepidula, collecting food both in its epipodial food-groove and 

 in a food-pouch. 



Capulus hungaricus exhibits an interesting variation of the same 

 manner of taking food. In this animal there is no epipodium nor food- 

 pouch. But instead of the former the lips have become elongated in 

 the form of a grooved proboscis, which appears to be held along the right 

 side of the animal to collect the food-particles from the tips of the gills 

 when the animal is feeding. The forwardly-directed stream is present on 

 the edge of the mantle in the inhalent chamber, but the stream is rela- 

 tively weak. There is an outgrowth of the foot between the propodium 

 and the "neck" region, known as the "operculum," which appears to 

 be used partly for side-tracking the food-current into the exhalent 

 stream when the animal is not feeding, but I have not yet had the 

 opportunity for investigating Capulus fully, and so must defer a 

 detailed account until later. 



The Hipponycidae are so similar in structure to the Capulidae as to 

 have been placed with them at one time in the same Order, and as they 

 live a sedentary life, it is almost certain that they will be found to feed 

 in some similar manner to that of Capulus. There is, therefore, little 

 doubt that all the Calyptraeidae feed in the same way as Crepidula, 

 and that the Capulidae feed in a similar manner : thus there is good 

 reason for suspecting that all sedentary Pectinibranchs may obtain 

 their food in the same or in a similar manner. 



XIV. THE CUKEENT-PEODUCING MECHANISM IN OTHEE 



GASTEOPODS. 



After seeing the gills of Crepidula, Calyptraea, and Capulus, and 

 especially the latter, whose gill is very similar to that of most 

 Gastropods, I was stimulated to examine all the sedentary forms to 

 be had. But, on seeing Pelseneer's figures of sections of the gills of 

 some Aspidobranchs (17, Figs. 99 to 104), I was induced to examine 

 all the Gastropods available. It was found that in all the forms 

 examined, namely, Fissurella, Haliotis, Calliostoma, Gibbula, Murex, 



