CHILOSCYLLIUM PLAGIOSUM. 63 



Form elongate, slender; tail longer than body; head short, crown and 

 forehead convex longitudinally and somewhat flattened transversely; snout 

 narrowing forward, short, blunt. Eye small, no fold in the lower lid. Spiracle 

 smaller than the eye, below the posterior extremity of the orbit, with a low process 

 on the edge. Nostrils with a nasoral groove; anterior valves and cirri reaching 

 the mouth, widely separated by the preoral attachments; posterior valves 

 forming a fold on the outer side of the nostril and continuing in a fold along the 

 outer side of the nasoral groove to end at the angle of the mouth with a very 

 short free end. Mouth with short lateral folds on both jaws around the angles, 

 and with a transgeneial fold behind the symphysis, covering the lower labial 

 folds, its hinder margin of considerable width and more or less scalloped. (Jill 

 openings narrow, hindmost widest, third to fifth above the pectoral, fourth and 

 fifth close together. Scales small, irregular, carinate, smooth on large individuals. 



Fins moderate; pectorals broad, margins and angles broadly rounded. 

 Dorsals subequal, hind margins nearly straight, angles not produced; origin 

 of first dorsal above end of base of ventral, distance from second less than twice 

 the length of the base; origin of second two lengths of its base forward of the 

 anal. Base of anal longer than base of second dorsal, equal to two thirds of 

 that of the subcaudal. Caudals narrow. Fin margins more convex on the 

 young. 



Greyish brown, lighter beneath, with about twelve irregular transverse 

 blotches of darker on the back: the first on the crown, the second between the 

 pectorals, the third at the tips of the pectorals, the fourth at the origin and the 

 fifth at the end of the first dorsal, the sixth at the origin and the seventh at the 

 end of the second dorsal, the eighth at the origin of the caudal, and the others 

 upon the caudal fin. On young specimens the anterior blotches enclose white 

 spots on the edge of the snout, at the side of the nostril, above each eye, and 

 two or more in each of the forward bands. The ground color is lighter on small 

 ones and on some dark spots are scattered over the body and white markings 

 on the edges of the fins. Adults are less spotted and are darker; some of them 

 nearly uniform brown. 



Specimens described here are from Hong Kong. Of other localities Siam, 

 while close to the Chinese, exhibits more and larger spots of light color; Singa- 

 pore types are more spotted with brown, the white spots also being present, 

 and the young have the brown blotches darker, the dark edges becoming scries 

 of spots on larger specimens. On Penang examples the ground colors are much 

 lighter and the dark edges of the blotches are more broken into series of small 



