61 



solution until a larger series of skulls of these species can be pro- 

 cured, and until the other parts of the skeleton can be compared ; 

 it being always borne in mind, at least according to my experience, 

 that the skulls and other parts of the skeleton of the animals are 

 quite as liable to vary in form and structure as any of the external 

 soft parts by which they are moulded. 



2. On the Genus Necturus or Menobranchus, with an 

 Account of its Skull and Teeth. By Dr. John Ed- 

 ward Gray, F.R.S., F.L.S., V.P.Z. &Ent. Soc. etc. 



Dr. Kaup lately sent to me the skull of the Proteus of the Lakes, 

 Necturus maculatus. As it presents some peculiarities, I am in- 

 duced to lay a figure and some observations on it before the Society. 



1 . It is the general belief of the inhabitants of Lake Erie that the 

 bite of the Proteus of the Lakes is poisonous. 



Dr. Holbrook observes that the fishermen regard these animals 

 "as poisonous, and are consequently seldom taken in hand." 



The Hon. Miss Amelia Murray in her ' Letters ' mentions this 

 animal as caught in a net at Detroit, under the name of Fish Lizard 

 (vol. i. p. 1 72), and observes : " The fishermen said its bite was very 

 poisonous, and it had the yellowish-brown lurid look which seems 

 to appertain to venomous reptiles ; but Dr. Kirtland says it is per- 

 fectly harmless." 



And this latter opinion appears to be the almost unanimous im- 

 pression of the naturalists of America. 



Yet the examination of the teeth will almost justify the popular 

 belief, and at least render it very desirable that the animal should 

 he examined in its living state, and that its bite be submitted to care- 

 ful experiment. 



The upper jaw of the skull is furnished with two series of small, 

 acute, uniform, nearly transparent, conical, slightly curved teeth, the 

 outer series being placed on the narrow intermaxillary bone, the 

 inner series on the front edge of the vomer and on the outer edge 

 of the lateral processes of the pterygoid bone. The lower jaw has 

 a single series of similar teeth, which lock between the two series 

 above described. 



All these teeth have a conical cavity on the hinder part of their 

 base, with a short linear slit on the middle of the inner side, and an 

 oblong perforation above the slit in the middle of the inner side of 

 the tooth. The form of these teeth is exactly similar to the fang of 

 poisonous Serpents ; that is to say, the cavity is not a hollow in the 

 substance of the tooth itself, but is formed by the sides of the teeth 

 being produced and folded together, leaving a conical cavity in the 

 inner side of the base, as is easily proved by the examination of the 

 teeth, which shows that the cavity is lined with enamel ; and the 

 junction of the two lateral expansions is rarely complete, but marked 

 by a more or less distinct or continued slit between the basal notch 

 and the subcentral foramen. In the poisonous Snakes the duct of 



