1 68 NATURAL SCIENCE. „^,._ 



limbs, abdomen, and tail of the animal are completely covered when 

 at rest. The latter peculiarity suggested the name of Cryptopns, 

 given to these aberrant Mysids by Latreille in 1829. They do not 

 appear to have been seen again for more than fifty years. M. Chaves 

 discovered them in the stomach of a dolphin-fish {Coiyphirna equisetis). 

 There are several specimens of the same species {Cryptopns defrancii) 

 in the British Museum, and Dr. J. E. Gray described them in 1830 

 as the type of his genus Cevataspis ; these fragments were obtained 

 from the stomach of a dolphin off" the coast of Brazil. 



The discovery of an elasipodous Holothurian in the Southern 

 Mediterranean has just been announced by Dr. E. von Marenzeller, 

 before the Imperial Academy of Sciences of Vienna. It is a colourless 

 species, scarcely 20 millims. in length, belonging to the family of 

 Elpidiidae, and apparently approaching the genus Kolga. Numerous 

 examples have been taken in three localities, at depths of 798, 943, 

 and 1,292 metres, but none are well preserved. The discovery is of 

 great interest, for the known Elasipoda are restricted almost exclu- 

 sively to the cold polar seas and the depths of the ocean : a single 

 exception to the rule is mentioned in the " Challenger " Report, 

 vol. iv., where Uyodi^mon macitlatus is recorded from the Philippines in 

 water at a temperature of 21° C. 



In the last part of the Quarterly Journal of Microscopical Science, 

 Mr. Beddard describes the structure of a new genus of Oligochacte 

 worm, named Branchiura on account of its nearly unique peculiarity 

 of possessing gills. The worm was found in the " Victoria Regia Tank " 

 of the Botanical Society's Gardens, in company with another very 

 remarkable worm, lately recorded from Madras by Professor A. G. 

 Bourne. The latter, which is a Naid, has also been quite recently 

 described in the same journal; it possesses outgrowths in the anterior 

 region of the body which enclose the bristles or setae, and are 

 probably gills in function, though they appear to suggest the para- 

 podia of the marine Cha^topods. In Branchiura the gills are limited 

 to the hinder segments of the body, and are dorsal and ventral in 

 position. There is a pair to each segment ; they are contractile and 

 recall the cirri of certain marine worms. The only other Oligochaete 

 known, besides the two just mentioned, which agrees with the Poly- 

 chaets in having gills, is Digitihranchus niloticus, recorded a great many 

 years ago from the Nile by the late Professor Grube. Unfortunately 

 the description of this creature is rendered nearly useless by the 

 absence of any account of its structure ; it is impossible to be certain 

 that it is not after all a Polychaete. Branchiura belongs to the family 

 Tubificidae, typified in this country by the common slender red worm, 

 Tubifex rivulorum, so abundant in rivers, ditches, and ponds. 



