The microscope and its revelations . uus. Thus in Dorispilosa, the centralband is almost entirely wanting, and each lateral band is formed of a singleFig. 267. pow of very large hooked teeth, setobliquely, like thoseof the lateral baudsin Fig. 267; whHstiu Doris tiihercu-lata, the centralband is the partmost developed, andcontains a numberof rows of conicalteeth, standing al-most perpendicu-larly, like those of aharrow (Fig. 268). 346. Many othervarieties might bedescribed, did spacepermit; but we mustbe content with add-ing, that the formFig. 26S. and arrangement of the teeth afford cha-racte
The microscope and its revelations . uus. Thus in Dorispilosa, the centralband is almost entirely wanting, and each lateral band is formed of a singleFig. 267. pow of very large hooked teeth, setobliquely, like thoseof the lateral baudsin Fig. 267; whHstiu Doris tiihercu-lata, the centralband is the partmost developed, andcontains a numberof rows of conicalteeth, standing al-most perpendicu-larly, like those of aharrow (Fig. 268). 346. Many othervarieties might bedescribed, did spacepermit; but we mustbe content with add-ing, that the formFig. 26S. and arrangement of the teeth afford cha-racters of greatvalue in classifica-tion, as was firstpointed-out by (of Stock-holm) in 1847, andhas been since verystrongly urged byDr. J. E. Gray, whoconsiders that thestructure of thetongue is one of thebest guides to thenatural afiinities ofthe species, genera,and families of tinsgroup, since any important alteration in the form or positionof the teeth must be accompanied by some corresponding- Palate of Trochus y^ /€ &J Palate of Doris tuberculata. TONGUES OF GASTEROPODS. , 607 peculiarity in the habits and manners of the animal.*Hence a systematic examination and delineation of thestructure and arrangement of these organs, by the aid of theMicroscope and the Camera Lucida, would be of the greatestservice to this department of Natural History.—The shortthick tube of the Limax and other terrestrial Gasteropods,appears adapted for the trituration of the food previouslyto its passing into the (Esophagus; for in these animalswe find the roof of the mouth furnished with a large stronghorny plate, against which the flat end of the tongue canwork. On the other hand, the flattened portion of thetongue of Buccinum and its allies is used by these animalsas a file, with which they bore holes thi-ough the shells ofthe mollusks that serve as their prey; this they are enabledto effect, by everting that part of the proboscis-shapedmouth whose floor is formed by the
Size: 1258px × 1987px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, booksubjectmicroscopes, booksubjectmicroscopy
