SPECIES OF MARINE PLANARIANS. 91 



a second at Pulo Daak, a small island between Labuan and the mainland of Borneo, 



August 25th. 



Fig. 4 : a, animal extended, upper surface ; b, animal extended, under surface ; c, eye-spots. 



5. Broceros Hancockanus, Coll. 

 Length T x % inch ; breadth -f%- inch. 

 Body velvety, opaque. 

 Upper surface of a deep velvety brown, edged with a double margin of equal widths, the 



inner deep orange, the outer opaque white. Along the centre of the back was a 



slightly elevated ridge. 

 Under surface grey, darkening towards the sides. 

 Head small, tentacles simply folded, long and graceful, the orange margin disappearing, 



and the white alone being prseent. 

 Eye-specks in an oval elongated cluster, immediately posterior to the head. 



A very beautiful species, no less from its rich colour than from its active movements. 

 Swimming by an undulating movement, it also floated on its back on the surface of the 

 water, after the manner of the Nudibranchiata. It crawled slowly, and with an undu- 

 lating motion. In texture it appeared somewhat translucent, and when suddenly dis- 

 turbed became much paler, as though by a sudden contraction of the tissues. In one 

 specimen a temporary slit appeared, occupying the middle third of the dorsal ridge, 

 rounded anteriorly, wedge-shaped posteriorly, through which slit the internal organiza- 

 tion was clearly visible. The slit remained open one day, and afterwards closed. The 

 intestines appeared sometimes as though protruding through this slit, which was not 

 exhibited by a second specimen. On placing one of these animals in glycerine, it imme- 

 diately discharged a quantity of a brownish-coloured fluid, and contracted considerably 

 in bulk. 



Two specimens were" obtained on succeeding days from among stones and old coral 

 blocks, between tide-marks, west of Singapore Harbour, Nov. 21st. 



This species I have much pleasure in connecting with the name of the late Mr. Albany 

 Hancock, the coadjutor of Alder, from whom, although we never met, I received many 

 kindly letters up to near the time of his lamented decease. 

 Fig. 5 : a, the animal in motion, exhibiting the open dorsal fissure ; b, the cluster of eye-specks. 



6. Broceros Buskii, Coll. 



Length ^ inch ; breadth ^ inch. 

 Body opaque, flat, smooth. 



Upper surface rich velvety olive-green, edged with pale yellow. 

 Under surface dark grey, the dendritic marking whitish, and occupying the anterior half 



of the median line. 

 Head with two folded earlike antenna! projections. 



Eye-spots in a circular cluster, difficult to detect owing to the dark colour of the animal, 

 and situated upon a ridge formed by the elevation of the antennal head. 



SECOND SERIES. — ZOOLOGY, VOL. I. O 



