386 [July, 



The spines near the extremities of the arms are, however, generally pointed. 

 Disk reddish, with black spots symmetrically arranged ; arms red, broadly annu- 

 late with black; spines pale brownish. Diameter, 4 inches. Found among 

 soft sponges in the circumlittoral zone. 

 Hab. Australia, at Port Jackson. 



2. Ophiothrix planulata. Disk and arms much depressed ; the latter in 

 length ten times the width of the former. Disk small, smooth and glossy above ; 

 arm-plates broadly triangular, separated from each other by a row of the small 

 plates with which the rest of the disk is covered. Below, the sides of the disk, 

 between the arms, are soft and covered with short spines ; the interbrachial 

 plates subrhombic, but not very distinct. The mouth-fissures have each two 

 large suckers, but no papillae on their sides. Arms suddenly tapering at the 

 middle ; their superior plates trapezoidal and minutely granulated ; lateral 

 spines five in each row, the middle ones largest, compressed, with blunt extremi- 

 ties, longitudinally striated, and denticulated on their edges. Disk dark green- 

 ish ; arms colored with red and light brown alternately : below white. Taken 

 in fifteen fathoms among dead corals, on " Groper Shoal," in S. Lat., 20 E. Lon. 



3. Ophiolepis perplexfs. Arms filiform, in length about seventeen times the 

 diameter of the disk. Dorsal surface of the disk covered with small scales, the 

 arm-plates of each pair being elongated, very narrow, broadest exteriorly, and 

 including a triangular space between them ; ventral surface with the inter- 

 brachial plates broader than long ; mouth with a pair of large scale-like papillae 

 at the summit of each projecting angle, and a pair at the base of each fissure. 

 Lateral spines of the arms five in number in each row, short, thick, and pointed. 

 Disk above dark greyish ; arms purplish-brown, darker and lighter alternately ; 

 below reddish. The disk is very soft and is always cast by the animal when 

 caught; the slender arms then twisting together in all directions. Found in the 

 circumlittoral zone in mud. 



Hab. Australia, at Port Jackson. 



4. Thyone buccalis. Subfusiform, of a brownish-grey color, with the suck- 

 erg small, uniformly distributed over the whole surface. Anus with five cal- 

 careous papillce. Tentacula much branched, ten in number, two of which are 

 much smaller than the rest. The oral column is the most remarkable feature in 

 this species, it being about one-half as long as the body, and consisting of a 

 flexible calcareous cylinder, contorted below, and sending ten short spurs of 

 points upward, and five pairs of long twisted ones downward. Its flexibility is 

 owing to the circumstance that its calcareous matter is deposited in the form of 

 irregular plates connected by softer parts. The inferior spurs thus seem jointed. 

 Length, 2 inches ; breadth, 0.35 inches. Taken near low water mark, under 

 stones. 



Hab. Australia, at Port Jackson. 



5. Chirodota Australiana. Small, and very slender ; surface covered with 

 papillae of two kinds ; the smaller and less conspicuous of which are spread 

 everywhere, and consist of accumulations of spiculse, which are hooked at one 

 extremity and slightly bent at the other. The larger kind are scattered, quite 

 thickly, along one side of the body only ; and are prominent, circular, white, 

 calcareous, varying in size from l-40th to l-20th of an inch in diameter ; they 

 are composed of accumulations of minute, sis-spoked wheels. The tentacula 

 are ten in number, each having ten serrulated digitations, placed on the outer 

 and the lateral margins of a sort of disk, which forms the anterior half of the 

 inner side of the tentacle. Color, pale yellowish. Length, 2 inches; breadth, 

 0.2 inch. Found under stones, near low-water mark. 



Hab. Australia, at Port Jackson. 



6. Synapta dolabripera. Slender, but rather short, of a dirty yellowish co- 

 lor ; skin very thickly provided with hook-bearing plates, which have usually 



