On new Coleoptera from East Africa. 2o9 



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

 history of Amphioxus is still found inscribed upon its 

 embryogenic development. Later on the tinimal 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 more ancient 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 Coleoptera from East Africa. 

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



The following interestuig new Coleoptera have been lent me 

 for description. 'l-^l»ey form part of a valuable collection 

 made by Mr. Hollis in Usambara in 189o and 1894. 



* Amphioxus iu 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 la 

 Amj}hiodU8 cultellus, from Torres Straits, and A. lucayanus, from the 

 Bahamas, for which have been founded the genera Epiyonichthys and 

 Asymmetron. 



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 (Cirrbipedes, Bryozoa, Echinoderms, Tunicates), in 

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

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

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



When, in passing from 07ie 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 attittide is capable of becoming 

 Axed and hereditarily transmitted. 



