80 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Feb. 23, 



like a portion of the "bone bed " found at the base of the Lias at 

 Coombe Hill. Shortly after this, I happened to be in the garden of 

 a fossil collector at Cheltenham, where there was a mass of Saurian 

 bones which had been for several months exposed to the weather, and 

 in the crevices of which, a black kind of matter had apparently 

 collected. Under the microscope, this appeared precisely similar to 

 that which I had noticed in my specimen. Owing to absence from 

 England and other circumstances, it was long before I had the oppor- 

 tunity of examining my other specimens. On doing so, I found I 

 had portions of three individual Ichthyosauri which exhibited the 

 same appearances. Some of the bones had a partial investment of 

 this substance, resembling in colour and thickness a coating of black 

 cloth. As I knew no one who had such an extensive and accurate 

 knowledge of minute organisms as Professor Quekett of the London 

 College of Surgeons, I forwarded some fragments to him, merely 

 stating that " they were found on cleaning fossils." As he had never 

 seen such like before, and having only small detached fragments for 

 examination, he could not at first give a decided opinion upon them ; 

 but upon my submitting to him more perfect specimens, and giving 

 him an account of how they were procured, his opinion fully coincided 

 with mine, that they had formed a part of the integument of the 

 Ichthyosaurus. Through his kindness, I have had some of the 

 specimens delineated by one of the practised artists employed at the 

 College of Surgeons. (See Plate V.) The outlines have been carefully 

 and accurately ti'aced by means of the camera lucida, and an inspec- 

 tion of the figures will give a better notion of the forms of the minute 

 bodies composing the carbonaceous layer, and of their relative size, 

 than any description could convey. 



In the best preserved specimens, this thin layer of black substance 

 (which appears to be all that remains of the skin, and was possibly 

 its external portion) consists of these minute bodies confusedly massed 

 or felted together in the interior of its substance, whilst on its external 

 surface they are more free and separate, and exhibit the largest 

 forms. In such specimens it is very difficult to detach them singly, 

 and I have been able only to get them isolated when they have been 

 separated from the mass and disseminated through the surrounding 

 sand and clay, and it is in such cases that the ,broken-off points 

 exhibit the tooth-like appearance above alluded to. "When grouped 

 together on the surface, they appear like hairs or spines ; but when 

 detached, by their short and generally flattened shapes, they approx- 

 imate more nearly to scales. 



As regards their structure, each of these minute bodies is composed 

 of a cortical and medullary 1 portion. The present condition of the 

 cortical portion is a black, opaque, carbonaceous substance, which 

 appears to have been originally a hollow body, and by subsequent 

 infiltration, carbonate of lime seems to have formed what may be 

 called its medullary portion or core. (See PI. V. figs. 6, 7, 8, &c.) 

 This last is soluble, with effervescence, in dilute acids, while the 

 former is unaffected by these agents, or by liquor potassae. 



Whether, therefore, these bodies should be classed with spines, 

 hairs, or scales, it might be difficult to determine, and indeed there 



