CHIROCEPHALUS. 43 



and terminated by several very fine short setae. They 

 are about the length of the head, take their origin from 

 its upper surface, a little above the root of the pedicle of 

 the eyes, and are directed upwards. They are jointed at 

 the lower third of their length, which adds to their 

 mobility, and are frequently put into motion by the 

 animal. The inferior pair (t. IV, f. B) are very remarkable, 

 and have been described by different authors as organs 

 totally different from antennae. Schceffer, who describes 

 them in the Branchipus, calls them tentacula, and 

 Latreille a sort of mandible ; while Prevost and J urine, 

 who describe them with their complicated attached 

 apparatus, call them hands. Their position, however, 

 upon the anterior segment of the head, seems, says M. 

 Edwards, to determine their true nature, though certainly 

 at first sight their conformation appears different from 

 what we usually see in these organs. They are essentially 

 prehensile organs, and consist chiefly of two large ap- 

 pendages which occupy the fore part of the head, and are 

 curved downwards towards the thorax. They are articu- 

 lated about the middle of their length, the first joint 

 being very large and fleshy, and having a short moveable 

 conical appendage on its external edge; the second being 

 curved, cylindrical, somewhat flattened at its extremity, 

 and having a strongly-toothed process at its base. 



Arising from the base of the first joint of each of these 

 appendages, we see another organ of a singular conforma- 

 tion (t. IV, f. c and c*). It was first distinctly pointed out 

 by Shaw ,and has since that been also described by Prevost. 

 By the former it is called the trunk, and by the latter the 

 second finger. They each consist of a long, flat, curved, 

 very flexible body, composed of numerous short articula- 

 tions, strongly toothed at its edges, and evidently con- 

 sisting of numerous muscular fibres. On the outward 

 edge of each, near the base, there are given off four rather 

 long and very flexible appendages, strongly toothed on 

 their internal edge near the extremity, and a large mem- 

 branous triangular-shaped body which, when extended 



