264 BRITISH ENTOMOSTBACA. 



from base to apex, and giving off two branches or rami, 

 each of three joints, provided with rather long, plumose 

 setae. The first and second of these joints have each one 

 very long seta springing from their base, and the terminal 

 giving off at its apex six of nearly equal length. The 

 third ])air (t. XXXIV, f. 5 m) is not unlike the preceding. 

 The basilar portion, however, seems to consist of only one 

 joint, which appears to constitute a lamellar appendage to 

 the lower part of the cephalo-thoracic portion of the body. 

 It gives otf two short rami, each single-jointed, and fur- 

 nished with plumose seta3. On the edge of the lower 

 part of this portion of the body there is a short spine or 

 hook, similar to that observed near the first pair of foot- 

 jaws. The fourth pair (t. XXXIV, f. 5;»^) springs from the 

 posterior thoracic segment of the body, and is very dif- 

 ferent from the preceding pairs, being more adapted for 

 tlie purpose of walking than swimming. It is slender, 

 elongated, and directed outwards ; consists of four joints, 

 and is simple, and not branched. The joints diminish 

 in size as they approach the apex, which is either in form 

 of a long, curved seta, with a row of short spines on its 

 inner edge, or a short joint terminating in three short setae. 

 On the median line of the body, between the last pair of 

 foot-jaws and first pair of feet, we observe a broadish 

 appendage (t. XXXIV, f. ^j), of a horny nature, generally 

 bifurcated, directed backwards, and capable of being 

 elevated or depressed. It is a sort of sternum. On the me- 

 dian line of last thoracic segment of the body, and toward 

 the posterior extremity, we see two somewhat similar 

 smaller horny tubercles, which M. Edwards considers 

 may be regarded as the vestiges of a fifth pair of feet. 

 From the external portion of the posterior part of this 

 segment also, on each side, in the female, we see the 

 external ovaries, two long cylindrical tubes, sometimes 

 two or three times the length of the whole animal. 



According to Pickering and Dana, the internal organs 

 of reproduction consist of a large pyriform organ, of a 

 glandular appearance, situate just anterior to the stomach, 



