1822.} Philosophical Transactions for 1822, Part LI. 467 
gestation ; and to the direct cause of parturition. It concludes 
with a specimen of a new mode of classing animals according to 
the difference in structure of the placenta; or where this is 
wanting, of the chorion ; and is illustrated with seven plates. 
yt. 9.0.9 em Geographical Situation of the Three Presidencies, 
Calcutta, Madras, and Bombay, in the East Indies; and 
XXXII. Of the Difference of Longitudes found by Chronome- 
ter, and by correspondent Eclipses of the Satellites of Jupiter ; 
with some Supplementary Information relative to Madras, Bom- 
bay, and Canton; as also the Latitude and Longitude of Point de 
Galle, and the Eviar’s Hood. By J. Goldingham, Esq. FRS. 
The following are the results of the observations described or 
enumerated in these papers. 
Long. E. of Greenwich. Lat. N. 
Madras, the Observatory.... 80° 17” 21”..., 18° 4’ 91” 
Madras, Fort St. George 
Sonuech steeples... - e524. gi ap! eR ae: sie ig 
Madras, the Fort Flag Staff.. 80 19 44 ....13 4 47 
Calcutta, Fort William.,.... 88 23 39 
Bombay, the Church.,..,... 72 54 43 ....18 56 .7 
Bombay, the Lighthouse..... 72 53 36 ....18 54 25 
Masulipatam Flag Staff. .... 81 12 24 .... -— 
Point de Galle Flag Staff.... 80 17 2.... 6 0O 50 
ie Priar’s\ Hood... . seve Ho Mali COs a rea gE 8 8 
WME oes woah cn a ve so o 0.n Aa Ss ae es ee or — 
On the coast about Madras, the tide seldom rises more than 
three feet ; and it is high water in the Syzigies at 9 25™; the’ 
variation of the compass towards the end of 1792 on the coast, 
about a degree to the northward of Madras, was 1° 3’ KE. 
At Bombay, the time of high water in the Syzigies at the 
Dock Head was 11" 32™; the greatest rise of the tide 18 feet ; 
medium rise of the springs 151 feet ; variation of the compass in’ 
the beginning of 1791, 42’ 59”, or 43’ W. 
XXXII. Observations on the Genus Planaria. By J. R. 
Johnson, MD. FRS. 
This paper relates to the natural history of four species of this 
genus: P. cornuta, P.torva, P. brunnea, and P. lactea; of 
which Dr. Johnson describes characters and habits, but we can 
only notice their manner of feeding, and mode of perpetuating 
their species. 
There are, in these curious animals, two ventral apertures, the 
upper of which gives passage to a long flexible tube, and the 
lower conducts to the ovarium ; the tube they frequently project, 
and it nearly equals the body in length. 
A variety of aquatic insects, worms, &c. being presented to 
some planarig, one of them, after the lapse of a few minutes, 
fastened upon a worm, immediately projecting and affixing this 
tube ; the worm being in this way closely retained, other plana- 
2H 2 
