Mr. J. Alder on some New and Rare Zoophytes. 311 
Superintendent of the Society’s Gardens, Mr. Negretti, Mr. 
Zambra, and myself, on different occasions. . 
Air in den, |Station of Thermometer.} Male, | Female.} Difference. 
Feb. 12 58°°6 | Surface of body. .| 70°2 | 73°0 | 28 
Between the coils | 7478 | 81°6 6°8 
Feb. 23 65°°4 | Surface of body..| 71°8 | 75%4 3°6 
Between the coils | 74°°0 | 83°°2 9%2 
March 2 60°°0 | Surface of body..| 71°6 | 84°°0 | 12%4 
Between the coils | 76°°0 | 96°°0 | 200 
March 9 61°°0 | Surface of body... | 72°8 | 79%5 6°7 
Between the coils}...... 86°°5 
March 16 | 66°0 | Surface of body. .} 72°4 | 77°°6 §%2 
Between the coils | 77°6 | 86°°0 | 8%4 
The male and female Python being in the same compartment 
of the reptile-house, and subject to exactly the same external 
influences, it appears evident that the increase of temperature 
from 6° to 20°, always observed in the case of the latter, can 
only be attributed to the process of incubation. But these 
observations do not confirm M. Valenciennes’s views as to the 
gradual decrease of heat towards the time for the eggs being 
hatched. 
XXXVII.—Descriptions of some New and Rare Zoophytes found, 
on the Coast of Northumberland. By Josuvua Auprr, Esq. 
[Plates XIII. XIV. & XV.] 
Order HYDROIDA. 
Fam. Tubulariade. 
Hydractinia areolata, n.sp. Pl. XIII. figs, 1-4. 
Polypary encrusting, consisting of a solid chitinous expansion, 
from which arise simple linear spines in irregular groups, leaving 
areolar spaces between them. Polypes naked, small, white, co- 
lumnar, slightly enlarging above, and terminating in a conical 
mouth, below which is a single circle of from six to ten linear 
tentacles, appearing of different lengths from their varying con- 
tractility. _Gonophores (reproductive organs) sessile on the chi- 
tinous base, large, globular, or slightly pear-shaped, containing 
each a single medusoid. Height of polype about 4, inch. 
Medusoid with a moderately deep subglobose umbrella, having 
four golden-yellow radiating canals, at the bulbous bases of 
which, on the margin of the umbrella, are four rather short ten- 
tacles; four shorter ones alternate with them ; and intermediate 
22% 
