Mr. L. Peringuey on new Coleoptera. 219 



individual appears to proceed from the union of the fragments 

 of the old one. In Dendrocometes, very probably, the new 

 nucleus originates in a somewhat different manner ; the 

 fragments of the old one dissolve (wholly or partially) in the 

 plasma, and separate again as a unitary body, very much as 

 crystals, under certain conditions, grow out of their mother- 

 liquor. 



An observation which I have frequently made upon Aselli- 

 cola is of theoretical importance, namely that sometimes three 

 individuals conjugate with each other by means of two canals 

 of union. It still remains to be ascertained, however, how in 

 this case the nucleus of the middle animalcule behaves towards 

 the other two nuclei. 



In our Acineta conjugation is by no means a rare pheno- 

 menon, as it is in almost all other Infusoria. In it, also, we 

 may speak of a sort of " epidemic," inasmuch as we are 

 pretty sure to find pairs upon all the branchial laminae of a 

 Crustacean if we observe them upon one. In general it is 

 middle-sized individuals that conjugate, while bud-formation 

 is the duty of the full-grown ones. 



EXPLANATION OF PLATE X., B. 



Fig. 4. Asellicola digitata, St., adult, X 540. 



Fig. 5, The same, comrnenciug bud-formation, X 235. 



Fig. 6. The same, a free bud from beneath. 



Fig. 7. The same, individual seeking conjugation, x 540. 



Fig. 8, The same, the end of conjugation, x 640. 



Figs, 9, 10. The same, stages of conjugation, x 640. 



In all the figures the letters have the following signification : — N., nu- 

 cleus ; 71., nucleolus; c. v., contractile vacuole ; ^., tentacles; ti., tinctin- 

 globules. 



XXVI. — Descriptions of some neio Species of Coleoptera in 

 the British Museum. By L. Pkringuey. 



Geodephaga. 

 Mantichora congoensis. 



Nigra, subnitida, capite magno prothoraceque antice atque lateraliter 

 punctatis ; elytris elongatis, subrectis, a medio ad apicem valde 

 deflexis et tuberculis acutis crebre tectis. 



Long. 40, lat. 18 mm. 



Size of M. tuberculata : head and prothorax similar ; elytra 



15* 



