MICROSCOPICAL MEMORANDA. 219 



the air-bladder in fishes generally, went on to describe that of the cod- 

 fish, which he stated to be a thick muscular bag, without any opening 

 externally, and provided, on its ventrical aspect, with a highly vascular 

 body, which has been supposed to perform the office of secreting the 

 air contained in the bladder. The author described the minute distribution 

 of the vessels in this so-called gland, the capillary system of which was 

 composed of a great number of parallel vessels, aggregated together in 

 bundles, and forming loops at the free surface of the gland ; and in the 

 other part of the bladder the arrangement was also remarkable for the 

 parallel manner iu which the vessels were disposed in this fish ; three, but 

 in others as many as six vessels, ran parallel to each other. The fact of 

 the air-bladder being subservient to the function of respiration, was sup- 

 ported to a certain extent, by the distribution found in the anterior com- 

 partment of the air-bladder of the eel. In this fish the vascular net-work 

 approached more nearly that of the cellular lungs of the Batrachia than 

 any other class of vessels. The author concluded by stating, that the 

 probable use of the gland in the closed air-bladders might be not that 

 of secreting air, but of keeping in a pure state the air already there, as 

 those fish provided with a gland generally live in deep water, and 

 from having no outlet to the bladder, are unable to change the contents, 

 should they become impure. The paper was accompanied with injected 

 specimens, and with diagrams of the most important parts alluded to by 

 the author. 



fKemoranfla. 



Cantor on the Infusoria met with at the mouth of the Canton river. 

 From comparison with M. Ehrenberg's great work upon Infusoria, it 

 would appear that most of the forms observed at the island of Lantoa, 

 situated at the mouth of the Canton river, and at Chusan, also inhabit 

 Europe. The new forms added, as " dubia," are those to which Dr. C. 

 has found none corresponding among Ehrenberg's. To G. W. Grant, 

 Esq., an indefatigable microscopical observer, who kindly examined the 

 sketches and notes made by Dr. C. of Chinese animalcules, he is in- 

 debted for the following list of forms described byM. Ehrenberg, which 

 Mr. Grant has recognized as also occurring in fresh water in and near 

 Calcutta : 



Sphferosira volvox. Naviculafulva. 



Closterium turgidum. turgida. 



Euglena longicauda. Vorticella patellina. 



Epipyxis utriculus ? Coleps hirtus. 



Arcelina aculeata. Lepadella emarginata. 



Arthrodesmus quadricaudatus. Brachionus urceolaris. 

 Micrasterias hexagona. 



From what has been stated, it will appear, that Indian forms (to 

 which may be added a few Javanese), prevail in the fauna of Chusan, 

 and that European forms make but a secondary feature. Annals of Na- 

 tural History, July, 1842,;?. 361. 



