520 Proceedings of the Royal Physical Society. 
The largest specimens of M. vulgaris known to Mr Boulenger, 
and recorded in his paper already referred to (p. 517), are— 
Male from Knockholt, Kent,—total length 104 mm., to cloaca 45, 
Female i 3 33 94 pt Ss 46. 
The largest examples I have examined were taken at 
Luffness, East Lothian, in the beginning of the present month 
(June 1894). Their measurements, immediately on being 
taken from the water, were— 
Male,—total length 97 mm., to cloaca 42. 
Female, “sf OF, ns 53 46. 
T ought to say, however, that the female, after being in a box 
for a day or two without water, was sent to Mr Boulenger, 
who made its length to be only 93 mm. The difference must 
have been due to shrinkage, for I feel sure there was no 
mistake in my measurement, which was repeated two or 
three times. The male. is in my aquarium, and still fulfils 
the original dimensions as given above. 
The measurements of a number of other examples which 
have passed through my hands recently are as under :— 
Male,—total 93 mm., to cloaca 42. Female,—total 94 mm., to cloaca 43. 
” ” 92 9 7 40. 22 2? 92 ” . 45. 
9) 23 91 39 9) 42, 92 2? 91 a2 a2 42. 
” ”? 90 ” ”? rir ” 2? 90 2? ” 41. 
oe 2? 90 ” ” as ” cB) 89 2 23 ri 
” 2 89 oe) oe) 40. 29 ” 88 29 ” ae 
” 2 89 ” ” 29. ” 9 87 ” ” 40. 
” 2 88 39 » 42. 3 ” 87 29 ” 40. 
9 39 88 ”) ” 37. 9 3 87 39 39 i 
9 ” 87 17 ” a ” 5) 86 +) 9 41. 
> i) 86 9 39 ve > ” 83 99 3 ae 
” ” 85 9 29 37. 29 a9 83 29 ”? 39 
” 39 84 ” 2) 39. 97 ” 81 99 iB) aay, 
7 2 $4 ” ” 38. ” ”? 81 ” 9 38. 
” ”? 82 +) ” ron 39 ” 80 ” » 37. 
2) be] 82 9 9 35, +B) ” 79 BR) 3) <a 
” ” 81 9 ” 37. ” a 79 79 ” 39, 
oY 29 80 By ”? 34. 9 7 78 ” oe) in se 
” a9 79 i) ” 36. 29 ” 76, 29 ” 37. 
76 9 2? ar 2 ” 29 73 9 ” 36. 
” ” 
The averages, including the two previously mentioned, 
alea 
Males,—total 86°3 mm., to cloaca 38°7. 
Females, ,,' 85°3 ,, 35 40°3, 
