326 Miscellaneous. 



even somewhat remote from the labial edge, the sixth and eighth 

 labials being in contact with each other (as in Diemennia, where this 

 shield is generally described as a temporal). An elongate temporal 

 shield is in contact with both oculars ; five scale-like temporals be- 

 hind, in two transverse series. Five pairs of the lower labials are in 

 contact with the chin-shields. 160 ventral shields; anal bifid; 

 66 subcaudals. 



The posterior maxillary tooth is the strongest, and somewhat re- 

 mote from the preceding. 



Light brownish olive, minutely dotted with brown. Anterior part 

 of the trunk with twelve pairs of brown spots, which are arranged in 

 a zigzag series ; the spots of the two anterior pairs are confluent. 

 Head brown, with a pair of rounded, well-defined, yellowish spots ; 

 a yellow line from above the eye, along the canthus rostralis, round 

 the snout ; upper lip yellow, separated from the brown colour by a 

 black line ; anterior ventral shields with an irregular series of black 

 dots on each side ; belly yellow. 



The typical specimen is an adult male, 16 inches long. I name 

 the species after my friend Dr. O. Wucherer of Bahia, its discoverer, 

 who informs me that he has seen only three specimens of it, alike 

 in size and colour. The species, therefore, appears to be scarce. 



MISCELLANEOUS. 



On the Acanthocephali. By Rudolph Leuckart. 



The Acanthocephali are the only group of Entozoa the develop- 

 ment of which has hitherto eluded the investigations of naturalists. 

 Dujardin and Siebold have indicated that the ova of the Echino- 

 rhynchi contain embryos very different from their parents ; but this 

 constitutes the whole of our knowledge, and the attribution to these 

 animals of a simple metamorphosis by Van Beneden and G. Wagner 

 is a pure hypothesis. 



Prof. Leuckart was struck more than once by the presence of an 

 imperfectly developed Echinorhynchus in the freshwater Gammarus 

 (G. Pulex), and he thought that he recognized a certain resem- 

 blance between this parasite and the Echinorhynchus Proteus of 

 the Carps. He therefore scattered the ova of six or eight Echino- 

 rhynchi of this species in a bottle containing Gammari, and in a 

 few days found a great number of these ova in the intestine of the 

 Gammari. He also found that the embryos quitted their envelopes, 

 pierced the wall of the intestine, and passed into the abdominal 

 cavity of these Crustaceans. These young worms are truncated an- 

 teriorly, and the truncated surface bears a double bundle of chitinous 

 spines. In the interior of the body there is an accumulation of oval 

 granules, previously indicated by Siebold as a constant organ of the 

 embryos of Echinorhynchi : Siebold regarded this organ as an un- 

 assimilated residue of the vitellus. To avoid prejudging, it may be 

 called the nucleus. 



The young embryo increases in size for about three weeks, after 

 which it undergoes a singular metamorphosis. Its nucleus is elon- 



