162 Mr. W. Clark on the recent Foraminifera. 



formed parasites as to baffle, as yet, any positive determinations 

 of the real animal inhabitant. It is necessary at once to describe 

 the animal of Dentalina linearis, an inhabitant of the coral- 

 line zone of the Devon coast, six miles from shore, in fifteen 

 fathoms water, as it appeared in a beautiful recent adult speci- 

 men of many chambers, that it may be referred to in illustration 

 of the additional observations I propose to make. I believe they 

 will be found more comprehensive than any that have hitherto 

 appeared on this very distinct section of the calcareous polypi. I 

 consider this animal and that of the Marginulina legumen as the 

 types of a great majority of the Foraminifera. 



Genus Dentalina, D'Orbigny. 



Dentalina linearis, Mont. 



Animal elongated, yellowish or pale red-brown ; it has a con- 

 tinuous subcylindrical membranous tube, coasting one of the 

 sides of the polyparium or shell from the posterior to the an- 

 terior chamber. The lobes or parenchymatous matter forming 

 the mass of the body of the animal are deposited in the palest 

 brown membranes, and fully fill each and every division of the 

 shell, being moulded on their forms ; these segments are united 

 to and open into the common canal, which appears to serve for 

 defsecation, the admission of aliment, as an oviduct, and to con- 

 vey moisture to the animal : the orifice thereof is in the adult 

 shell terminated by eight slender equidistant pale red pointed 

 minute tentacula. 



In the genial season, July and August, each lobe on its flat 

 surface is marked with a circle of deeper red than the other part, 

 and which I may safely term a gemmiferous pullulation, as 

 therefrom a line of minor gemmse is seen proceeding from each 

 bud to the margin of the common canal to discharge therein 

 these undoubted germs of reproduction. Thus far, as regards the 

 animal, no doubt can exist ; but with respect to respiration, the; 

 circulation, the mode of growth of the animal and polyparium, 

 these points must be received with caution, as they have not the 

 test of certainty, though I believe they are substantially correct. 

 I now state what I have perceived of the increase of the animal 

 from segment to segment, and the corresponding formation of 

 the same parts of the polyparium. In the examination of nume- 

 rous specimens of this species and of Marginulina legumen, in 

 which the last chamber was incomplete and not domed over, I 

 have seen at the neck of the antepenultimate chamber a mem- 

 brane encircling and lining the unfinished wall, and a mass of 

 parenchyma adjacent, and apparently growing pari passu with 

 the common membranous tube, which is always kept free and 

 open, and thus the lobe, tube and chambers are gradually formed 



