102 [October, 



and sub-divisious are moderately well-defined, the skin puckered a 

 a little and dimpled along the sides, the ventral and anal legs fairly 

 well developed, each foot being furnished with a complete circlet of 

 fine hooks ; in colour, the head is pale translucent brown, the lobes 

 margined with a reticulation of darker brown, and a similar sti'eak in 

 the middle of each ; the mouth is blackish-brown, sometimes there is 

 a spot of this dark colour on the triangular space above it, the ocelli 

 large and black ; the second segment, yellow or olive-yellow, has some- 

 times a few brown freckles, and a thin transverse streak of brown at 

 the hind margin, and a few fainter freckles on each side the dorsal 

 region ; all the rest of the body is of a bright, deep yellow, or else of 

 olive-yellow, but so translucent as to show very distinctly through the 

 skin, not only the broad and blackish-olive internal vessel sliding to 

 and fro, but also the paler trachea, with its larger branches, and the 

 multitude of excessively fine ramifications ; in the more olive tinged 

 examples there occur two parallel brown streaks low on the sides of 

 the second, third, fourth, and fifth segments, sometimes most marked 

 on the fourth and fifth ; the spiracles are of the ground colour, ringed 

 with brown ; some extremely minute hairs, one in each usual tuber- 

 cular situation, can onlv be seen with the aid of a powerful lens. 



When the larva has fed up on the soft, narrow, ribbon-like, floating 

 leaves of S. simplex, it cuts off a couple of pieces of the plant, varying 

 in length from about three-quarters to nearly an inch, without regard 

 to their being equal in size, these it spins securely together and moors 

 with silk near the edge to a floating leaf ; the puparium thus made 

 lies horizontally, pai'tly or entirely submerged. 



But when 8. ramosum is the food-plant, the larva chooses a situa- 

 tion close to the outside edge of a leaf in an almost perpendicular 

 position, and there, low in the water, attaches a piece of the plant, 

 broader at the lower than at the upper end, and draws it round itself 

 close to the leaf, on which it looks like a natural excrescence, being about 

 an inch and a quarter in length, rather bluntly rounded off below, and 

 for half an inch tapering to a point above. 



The cocoon is of white silk, apparently quite diy within and 

 closely enveloping the pupa with the old larval skin sticking behind ; 

 the pupa itself is a trifle over three-eighths of an inch in length, of 

 moderate slenderness, the head well produced, the back of the thorax 

 gently rising from it, and from thence the width is uniform to the 

 ends of the wing-covers ; these, though well defined, are pressed close 

 to the body ; the abdomen begins to taper from the tenth segment, to 

 which the ends of the leg-pieces reach, ]*rojecting free ; the tip of the 



