176 Proceedings of the 



II. On the Structure and Habits of the Slow-Worm (Anguis 

 fragilis, Linn.) By Daniel R. Rankin, Esq., Carluke. 



From what is recorded in works of reference, the slow-worm 

 (Anguis fragilis), though the most accessible and easily 

 managed of the reptile kind, seems to have engaged the par- 

 ticular attention of few naturalists. 



During several years, from daily observation of many indi- 

 viduals of uncertain age, and in every stage of development, 

 from the egg till the seventh year, having accumulated a con- 

 clerable number of facts regarding the economy of this inter- 

 esting little animal, I am enabled to give some details which 

 may serve more fully t elucidate its history. 



The generic position of the slow-worm is well determined ; 

 but as general descriptions seem to have been drawn from 

 limited sources, from young or mutilated specimens, or from in- 

 dividuals in some phase of periodic change, confusion appears 

 to exist ; and in other particulars there is uncertainty or error. 



To secure clear and distinct delineations of objects in Na- 

 tural History words are seldom adequate ; but as the aspects 

 of this animal, within description, may be better given if 

 spoken of under divisions, that method shall be followed. 



1. Form. — The mature animal, as it is found in Clydesdale, 

 is from 17 to 20 inches in length, and attains to this about 

 the fourth, although its other dimensions are not fully reached 

 till about the seventh or eighth year. It has a small, elonga- 

 ted, somewhat angular and conical head ; mouth of almost 

 equal length with the head ; eyes lateral, oval, distinct, 

 though not prominent ; ruby iris ; eyelids, and a moveable 

 membrane within eyelids (membrana nictitans) ; nostrils la- 

 teral, directed vertically, and situated in the second scale of 

 the second row of the marginal labial scales of the upper jaw, 

 the scale being reflected into the aperture. The neck is short, 

 and at times is observably smaller than the head, as in the 

 act of inspiring, drinking, &c. The body, from the neck, gra- 

 dually swells to the middle, then gradually declines in thick- 

 ness to the cloaca, and from thence becomes smaller and 

 smaller to the extremity of the tail, which ends a little short 

 of a minute point. A specimen before me, a female fourteen 



