90 DR. COLLING WOOD ON THIRTY-ONE 



3. Sphyngiceps lacteus, Coll. 



Length - x 7 o inch ; breadth | inch. 

 Body graceful in form, semitransparent. 

 Upper surface cream-coloured, irregularly spotted with sparse and minute black dots, 



and having faint marbling on either side of the median ridge, which is very con-« 



spicuous. Margin irregularly blotched with red, and the whole body edged with a 



narrow black line. 

 Under surface whitish, edged with red blotches and a black streak as on the upper side, 



but somewhat less distinct. A broad streak of white occupies the anterior third 



of the median line. 

 Head small and narrow, but rendered very conspicuous at times by its being raised up, 



so that the median ridge is thus very much elevated in front. Head furnished 



with two folded tentacles. 

 Eye-spots round, immediately posterior to the head, which has in front of it a pair of 



larger single spots. 

 This is a remarkably graceful little animal, crawls with great rapidity, and with a 

 gliding movement, then suddenly throws its head back, and, leaving the side of the vessel, 

 swims with a graceful serpentine movement, sometimes very fast ; floats also on its back 

 on the surface of the water. It has the habit of throwing back its head very far, and 

 remaining in that position [rampant, as it were), at which time the head and anterior 

 portion of the body become narrow and tabular, giving the appearance of a neck. When 

 at rest it expands laterally, becoming in shape as broad as long. 



One specimen found under a coral block, west of Singapore Harbour, at low water, on 

 Nov. 22nd. 

 Fig. 3 : a, animal in motion ; b, head, enlarged, showing eye-spots. 



4. Tracer os concinnus, Coll. 

 Length f inch. 



Body narrow, entire, without marginal foldings. 



Upper surface cream-colour, approaching to yellow, with an edging of blue all round, 

 composed of small and larger spots running into one another. A similar blue streak 

 runs along the median line from a little behind the head to some distance from the 

 posterior extremity, through about three quarters the length. 



Under surface cream-colour, similarly edged with blue, a brownish streak running 

 through the whole median line, the arbusculiform alimentary tube of a straw- 

 colour, occupying the anterior third. 



Mead with two folded tentacles. 



Eye-specks conglomerated in a small round spot midway between the head and the blue 

 median line. 

 A very pretty and lively species, particularly fond of floating on its back or crawling 



rapidly along. I obtained one specimen on a reef at Labuan, near low-water mark, and 



