On the Dipterous Genus Xylomyia, Rond. 181 



the ' Oceanic Ichthyology ' (p. 205, fig. 215) under the name 

 of Benthodesmus atlanticus. The species was founded on 

 specimens obtained on the western edge of the Grand Bank 

 of Newfoundland, off St. Kitts, W.I., and in mid-North 

 Atlantic, at depths varying between 25 and 20S fathoms, and 

 previously referred to Lepidopus elont/atus, Clarke. I am 

 now able to report its occurrence at Madeira and on the coast 

 of Portugal, whence it has been inadequately described and 

 figured by Vieira as Lepidopus argenteus, Bon. (Ann. Sc. 

 Nat. Porto, i. 1894, p. 165, pis. ix. & x.). 



Mr. Arendrup had fully realized the interest that attaches 

 to the Madeira specimen, which represented an unnamed 

 species at the time he obtained it, and he had drawn up some 

 notes which I here reproduce in an abridged and slightly 

 altered form, after verification on the original. 



Depth of body 22 times in total length, length of head 6§ 

 times. Vent marking | on the total length. Occipital crest 

 very feeble ; eye 6 times in head, 2i in snout ; lower jaw 

 projecting, with a fleshy appendage anteriorly ; teeth acute, 

 compressed, 19 in upper jaw (including 2 large anterior 

 fangs), 20 in lower jaw, without any larger ones. 7 branchio- 

 stegals. Gill-rakers few, widely separated. Dorsal with 

 about 156 rays, beginning halfway between eye and root of 

 pectoral, the longest rays not quite so long as diameter of eye. 

 Anal with 26 free rays. Ventrals represented by minute 

 scale-like scutes. Pectoral 3 times in length of head. 

 Caudal small, forked. Caudal peduncle depressed, 5 times 

 in length of head. Uniform silvery ; margin of dorsal black 

 for the first 10 or 12 rays. 



XXX. — On the Preliminary Stages and Mode of Escape of the 

 Imago in the Dipterous Genus Xylomyia, Rond. (Subula, 

 Mg. et auct.), with especial reference to Xylomyia macu- 

 lata, F. ; and on the Systematic Position of the Genus. By 

 E. E. Austen, Zoological Department, British Museum. 



I. 



Preliminaey Stages and Mode of Escape of the Imago. 



Through the courtesy of the Rev. H. S. Gorham the new 

 collection of British Diptera in the National Museum has 

 recently been enriched by a (J) specimen of the rare fly 

 Xylomyia maculata, F., together with its puparium and the 

 skin of the pupa from which it was bred. 



