ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 45 



pelagoes that may have extended, under uniform conditions, north of 

 the Equator, from Panama eastwards, by way of Africa, into South - 

 East Asia. Of this sea the hermit-crabs in question might be supposed 

 to be part of the residual littoral or sub-littoral fauna, while Herpele 

 might be one of the relics of the land-fauna of its southern coasts. 



Cranial Osteology of Fishes.* — W. CI. Ridewood describes the 

 skull in the families Mormyridse, Notopteridae, and Hyodontidae. He 

 considers that these families, though more closely related inter se than 

 is any one of them with any other family of Malacopterygian fishes, 

 are not more intimately related with one another than was previously 

 assumed to be the case. As far as cranial characters are concerned, 

 they afford no basis for a phylogenetic arrangement. The three families 

 must remain, as hitherto, the terminals of a radiating system. 



Edestus and its Relatives.! — C. R. Eastman refers to the uncer- 

 tainty as to the nature of Edestus fossils, some authorities referring 

 them to the jaws, and others to the external armature of an Elasmo- 

 branch. He has been able to show that the fused segments of Edestus, 

 Campyloprion, and Helicoprion are veritable teeth corresponding to the 

 symphysial series of Gampodus, which are enormously enlarged as com- 

 pared with those of Cestracion and other recent sharks ; and also that 

 these four Carboniferous and Permian genera together constitute a 

 remarkable series, in which the progress of evolution is readily traceable. 

 Beginning with Campodus, he shows in the species of Edestus and 

 Campytoprion the progressive stages by which the typical orodont 

 dentition of the Lower Carboniferous passed into the excessively 

 modified spirals of Helicoprion before the close of the Palaeozoic. 



Natural History of Amia calva.J — Jacob Reighard has made a 

 careful study of the habits — especially the breeding habits — of this fish. 

 The sexes differ in colour ; about three times as many males as females 

 come to the spawning ground ; the nests are built, mostly at night, by 

 the males : each nest is the property of an individual male, who guards 

 and defends it. 



Spawning usually occurs at night ; sexual excitation of the female 

 is produced by the biting and rubbing, of the male ; the male may get 

 two females to spawn in the same nest ; the larvae leave the nest in a 

 swarm with the male and appear to follow him by scent. The larvae 

 are black until they are 30 to 40 mm. in length, and a school of black 

 larvae when separated from the male begins to circle and continues to 

 do so as a whole or in fragments until re-united with the male. "When 

 about ?•() to 40 mm. long the black larvae begin to show orange and 

 green colours. The schools of bright-coloured larvae move more rapidly 

 in the water, do not circle in search of the male, and are not closely 

 guarded. Schools of larvae of greater length than 100 mm. have not 

 been observed ; the schools probably disperse when the larvae are about 

 this size. 



* Journ. Linn. Soc. (Zool.) xxix. (1904) pp. 188-217 (4 pis.) 

 t Mark Anniv. Vol., 1903, pp. 279-89 (1 pl.).j 

 X Tom. cit., pp. 57-109 1 pi. aud 1 fig.). 



