Description of a New Dipterous Insect. By J. Dehy. 181 



tion, but once discovered they are easily recognized ; tte black, very 

 long-legged males looking like minute spiders, while the dingy brown 

 louse-like females which they drag after them, have the appearance, 

 from a distance, of the cocoons some spiders carry behind them. 



As was kindly pointed out to me by Mr. C. Waterhouse of the 

 British Museum, this insect is exceedingly similar in its habits to 

 Halirytus amphihiuSjdiscoYeved by the Kev. A. E. Eaton, in Kerguelen's 

 Land, and which was fully described in vol. clxviii. of the Phil. Trans, 

 of the Eoyal Society (special volume on the Zoology of Kerguelen 

 and of Kodriguez), p. 24, pi. xiv. fig. 6. It is, however, generically 

 distinct from its antipodal representative, although belonging to the 

 same group of aberrant Chironomidfe, in which the antennae are 

 only six-jointed and unfeathered. 



Dr. A. S. Packard has described another marine dipterous insect 

 under the name of Chironomus oceanicus, the larvae of which he 

 found on floating " eel-grass " and in green sea- weed at low-water 

 mark in Salem Harbour, U.S.A. Besides the two-winged insects 

 above named, several more have been noticed, and among these : — • 

 Ephydra calif ornicus, Ephydra gracilis, Ep)hydra halophila, as well 

 as the larvae of a species of Tanypus and of a Stratiomys, all of 

 which were inhabitants of salt water. Nothing further is known of 

 their respective life-histories. 



I have some remembrance of having myself seen, very many years 

 ago, a very similar insect, running over sea-weed and mussels, upon 

 the Ostend breakwater at low tide. If looked for in this site, I should 

 advise that this be done during the first days of spring, as it no doubt 

 is a precocious insect. 



As Psamathiomya pectinata will probably be found to live on 

 other shores besides those of Biarritz, I have, in order to facilitate 

 identification or comparison, prepared the following description of the 

 insect which forms the subject of this communication. 



Genus.— PSAMATHIOMYA. 



Characters. — Antennae six-jointed in both sexes, three middle 

 joints submoniliform, neither feathered nor plumed, much shorter than 

 the head and thorax ; mesonotum cucullate, projecting over the 

 head ; legs very long and slender, especially in the males, the terminal 

 joint of the tarsus being furnished (along with the usual claws), with 

 a special finger-like projection, extending over and between the claws, 

 while a doubly curved curious comb-like appendage faces it from 

 below. 



Wings rudimentary; much smaller in the females than in the 

 males ; without nervures. Halteres distinct. The convex eyes are 

 distant in both sexes, but farthest apart in the females. Both 

 the ordinary claws on the end joint of the tarsi in the male are 

 deeply cleft or bifid ; those in the female being simple. The comb- 

 like appendages are similar in both sexes. 



