inhabiting Salt Water. . 233 



down on the underside of tlie head, between the inner and 

 outer lobes. Mandibles not distinguishable. The mouth-parts 

 are all inserted beyond the middle of the head. The body is 

 rather flattened and broadest just in front of the middle ; the 

 segments are quite convex, with the sutures well marked. A 

 pair of well-marked stigmata on the prothoracic ring ; none 

 behind. The body is horn-coloured, paler beneath, with the 

 integument densely punctured ; the upper surface of the body 

 is marbled with alternate light and dark streaks, in the middle 

 of the body fading out in the middle of each segment, but to- 

 ward the end of the body disappearing toward the sutures. 

 On the side of each segment are four rows of minute dark 

 dots, the upper row passing over the back at nearly right 

 angles, meeting the one opposite on the median line of the 

 body. The anal segment is broad and flat, square at the tip, 

 but a Kttle rounded at the corners ; it is nearly as long as the 

 greatest width of the body. From a transverse terminal slit 

 (not seen from above) projects a group of about ten radiating 

 respiratory filaments, white and finely ciliated to the tip, the 

 filaments being eacli a little over half as long as the anal seg- 

 ment. A little within the middle of this segment is a rather 

 long slit, with thickened chitinous edges. A few hairs of 

 varjdng length are scattered over the body. Length '80 of 

 an inch. This is, so far as I am aware, the first instance of 

 the occm'rence of this genus in salt water. 



Ephydra californica, n. sp. — Several specimens of the larva? 

 uf this species occuiTcd, though the pupai were far more nu- 

 merous. Unfortunately, none of the adults were found ; but 

 as the puparia are abundant, and the flies could easily be 

 reared from them, I venture to name the species. 



The larva closely agrees with that of the European E. ripa- 

 ria, Fallen, described by Loew, but has one more pair of ab- 

 dominal legs or tubercles. The body is white, long, and 

 slender, cylindrical, the sides of the segments bulging out ; 

 and each abdominal ring has three transverse, broad, flat, 

 tergal ridges, the thoracic segments being smooth above. The 

 anterior end of the body, including the thoracic rings, tapers 

 gradually, being subconical and truncated abruptly. The 

 three thoracic segments are smooth, but minutely hairy on the 

 anterior edge, the hairs being similarly arranged on the abdo- 

 minal segments. The head is very small ; the mandibles 

 exist in the form of acute, curved, chitinous hooks, with a 

 pair of papilliform antennae (?) behind, and a pair of shorter 

 tubercles (rudimentary palpi ?) in front of them and just behind 

 the mandibles *. The upperside of the body and base of the 



* These parts need to be studied in the living insect; they are not 



