On new Culeoptera from East Africa. 259 



by heredity {Lamarck' 's principle), and this phase in the 

 history of Amphioxus is still found inscribed upon its 

 embryogenic development. Later on the animal adopted the 

 habit of burying its posterior extremity in the sand; it found 

 itself subjected to a life in a homogeneous medium ; the sym- 

 metrical shapes, acting in harmony with a moreancieut heredity 

 unopposed by contrary efforts, and in accordance even with the 

 conformation of the regions of the body which have escaped 

 the torsion, caused the mouth, by means of successive distor- 

 tions, to take its place in the plan of symmetry, and, since it 

 was unable to regain its position in the dorsal median line, it 

 passed over to the ventral side. Thus was brought about the 

 new attitude and the return to a perfect symmetry on the part 

 of the Vertebrates descending from Amphioxus or from 

 analogous Vertebroids *. 



XXX. — Descriptions of new Goleoptera from East Africa. 

 By C. O.Waterhouse, F.E.S. 



The following interesting new Coleoptera have been lent me 

 for description. They form part of a valuable collection 

 made by Mr. Hollis in Usambara in 1893 and 1894. 



* Amphioxus in the adult state has not yet recovered this symmetry, 

 as is shown by the presence on the left side of the body of a single olfac- 

 tory pit, the continuity of the right half of the oral hood with the cephalic 

 expansion of the fin, the continuity of the right metapleure alone with 

 the ventral fin, the overlapping of the right and left muscle-segments, 

 and, finally, the abortion of the genital organs of the left side in 

 Amphioxus cultellus, from Torres Straits, and A. lucayanus, from the 

 Bahamas, for which have been founded the genera Epiyonichthys and 

 Asymmetroyi. 



The inductions by means of which we have interpreted the phenomena 

 of torsion which are proved to take place in the development of Amphi- 

 oxus, and the deductions which we have drawn from these phenomena 

 with reference to the history of the reversal of the Vertebrates, are but 

 strictly scientific applications of general laws, recognized by all in prin- 

 ciple, but too often forgotten in each particular case. We observe, more- 

 over, phenomena of torsion, which are analogous to the above and are 

 explained by the principle of Lamarck, likewise in the development of 

 many fixed animals (Cirrhipedes, Bryozoa, Echinoderms, Tunicates), in 

 the case of the Gastropod moilusks and the Pleuronectid fishes. The rule 

 which governs all these phenomena, and which may be termed the rule 

 of the fixation of attitudes, may be expressed thus: — 



When, in passing from one mode of life to another, an animal is led, in 

 order to ensure that its organs shall perform their functions properly, to 

 assume habitually a definite attitude, this attitude is capable of becoming 

 fixed and hereditarily transmitted. 



