65 



Professor Xing contends that, what whatever office the filaments may 

 subserve, the circumstances under which they occur are obviously in- 

 compatible with their supposed ciliary function; and in his opinion the 

 evidence he has adduced shows that they are the ultimate subdivisions of 

 caecal appendages. 



The perforations themselves, or rather their trunks, are generally 

 simple ; but in Terebratulina caput-serpentis^ hitherto stated to have 

 them of the usual form, they are singularly branched, or antler- 

 shaped. 



Although something has long been known of the branching cha- 

 racter which distinguishes the canal system of Crania anomala, addi- 

 tional information on this point is given in the paper. Each trunk is 

 at first divided somewhat as in Terebratulina caput-serpentis ; but the 

 branches, instead of ending each in a brush-like bundle, are individually 

 terminated with a tuft of branchlets, sub-radially disposed. The 

 former, as commonly seen, no doubt differs considerably from the latter: 

 this is not so, however, when the respective bundles of various species 

 are examined with powers magnifying from 150 to 300 diameters : — 

 for example, in Terebratida vitrea the radiating lines or tubules, besides 

 seemingly branching, shoot right across the comparatively wide inter- 

 spaces, thereby causing the bundles to resemble long-spined acari, and 

 to assume a feature which shows that there is nothing real or absolute 

 in the difference above alluded to. 



As the branchlet-tufts of Crania anomala are obviously the ultimate 

 subdivisions of the perforations, the same conclusion may be predicated 

 of the brush-like bundles belonging to the so-called " ciliated discoidal 

 opercula" of other Palliobranchs : in short, according to Professor King, 

 both are strictly homologous structures. 



The paper notices some other points, which, along with those just 

 stated, show that, although much has been published on the history 

 of the Palliobranchiata, the subject has been far from exhausted. 



XIY— Ox AxnrAL Heat. By W. H. O'Leaey, Esq. [Abstract.] 



[Read May 13, 1867.] 



Theee are, broadly speaking, three great sources whence we derive 

 materials which, by being oxidized, produce Animal Heat : — 



First. Calorifacient foods, fats, &c, ingested by the intestinal 

 canal ; 



Second. Disintegrated material derived from muscular and other 

 tissues, as a result of activity ; 



Third. Reserved calorifacient materials stored up in the living 

 system — namely adipose, &c. 



The result of a number of experiments detailed in this paper (some 

 of which I would wish to repeat in order to verify the results), tend to 

 conclusively prove that the production of Animal Heat by oxidation of 



Ec I. A. PEOC. VOL. X. K 



