TF. Davies — On Squalor aia. 149 



portion of tlie snout it measures 2| inclies, the snout being 2| inclies 

 long. Dr. Giinther considered this specimen to be most probably 

 the remains of the head of the female. 



That the dermal integument was extended on either side from 

 the head tc the anterior extremity of the snout, so as to form a coni- 

 cal beak or " cutwater," as in Bhinobatiis, is evidenced by portions 

 of the skin being preserved in front of the head (Fig. 1), and also a 

 small portion on the detached snout. As we have already observed, 

 the rostral cartilages are much more robust in the male than in the 

 female ; and especially that there is in that of the former a deep 

 depression at the posterior end for the reception of the spine. 



It is obvious from these characters that the snout was capable of 

 offering a considerable amount of resistance to the spine, assuming 

 that the functions of the latter subserved the same purpose as its 

 analogue on the head of the Chimceridce ; a feasible assumption, from 

 the fact that there are no indications of the powerful claspers that 

 are possessed by the males of most species of the Eays, neither in 

 the Bristol specimen, as noticed by Dr. Eiley, nor upon that in the 

 British Museum ; and, also, that there are attached to the cartila- 

 ginous processes, on either side of the snout, a number of tubercles 

 with recurved booklets ; and, moreover, that similar tubercles line 

 the inner sides of the hollow formed by the ridges at its base (Fig. Ih,). 

 The spine has also three or four of these hooked tubercles adhering 

 to its sides ; they were probably more numerous originally, but have 

 become detached by maceration. This armature was as well 

 adapted for the firm retention of the female as the analogous hook- 

 lets of the rostral claspers of the Chimoerida.^ 



But whatever the functions, the possession of this rostral spine is a 

 peculiar feature, at present utterly unknown as occurring, even in 

 a rudimentary form, in any other recent or extinct Shark or Kay. 

 And it may ultimately prove to be of more than generic distinction 

 among the Baiidce. 



The short and numerous vertebrae are also- characteristic. In the 

 Bristol specimen the vertebral column is imperfect; nevertheless. Dr. 

 Eiley counted 260 vertebrae, which he thus apportioned : cervical 28, 

 dorsal 143, caudal 90. That in the British Museum has the spinal 

 column nearly entire, only the extreme end of the tail is missing. 

 It is 12 inches long, and has 370 vertebrae; they cannot be apportioned 

 with certainty on account of the absence of the transverse elements 

 of the scapular arch, but there are about 150 between the occiput 

 and the pelvis ; not quite so many as Dr. Eiley assigns to the cervical 

 and dorsal regions. Kear the lumbar region of the back, where the 

 vertebra appear to be the largest, there are 31 in the length of one 

 inch, and 35 in the same space in the tail, so that when entire the 

 number probably exceeded 400. This specimen is in some respects 



1 It is an interesting fact in connexion with our subject, that Sgualoraia and a 

 Chimceroid species {Ischyodus wthorhinus, Egert.), in which this organ attained its 

 maximum development, were contemporaries, both being found in the same Lias 

 deposit at Lyme Regis. See a Paper on a "New Chimieroid Fish," by Sir Philip 

 Egerton, Quart. Journ. Geol. Soc, vol. xxvii., p. 275, pi. xiii. 



