1903.] ON THE HAIR-SLOPE IN MAMMALS. 79 
Fig. 2d. The basal parts of the three posterior thoracic legs, the branchie above trl2— 
trl.4, and the lower part of the two anterior abdominal segments, from the 
side; X 11. The lettering of the branchiw as in fig. 6d on the preceding 
Plate. 
2 e. Left mandible, from below; X 13. 
2f. Left first maxilliped, from below; x 13. 
2g. Middle part of the first maxilliped, from above; X 44. 01, upper proximal 
luminous organ ; 0°, distal luminous organ seen through the endopod. 
2h. Left second maxilliped with its epipod and branchia, from the outer side ; 
x 13. 
2%. The three posterior thoracic segments and the two anterior abdominal 
segments, from below, showing 31 luminous organs; xX 9. Of the 
pleopods, only the basal joint—with its huninous organ—has been drawn. 
2k. Sixth abdominal segment with the basal part of the telson and the uropods, 
and the posterior part of the fitth abdominal segment with a part of the 
pleopod; X 13/2. 
21. Exterior branch of the left uropod, from the outer side; 17/2. The 
apical part is wanting. 
2m. Luminous organ from the side of the thorax near 67. above trl.3, seen in 
optical vertical section; X 180. a, chitinous lens; a!, its thinner 
external layer; 6, inner lens; ¢, thin layer between the inner lens and the 
thick glandular layer d; e, reflector; f, enveloping thin layer. 
2n. Sketch of the luminous organ from the upper side of the first maxilliped ; 
x 180. a, lens, partly overlapped above by the protruding chitinous 
plate 2. 
February 3, 1903. 
Howarb Saunpers, Esq., F.L.S., Vice-President, 
in the Chair. 
The Secretary read the following report on the additions to the 
Society's Menagerie during the month of January 1903 :— 
The registered additions to the Society’s Menagerie during the 
month of January 1903 were 58 in number. Of these 15 were 
acquired by presentation and 9 by purchase, and 34 were received 
on deposit. The total number of departures during the same 
period, by death and removals, was 120. 
The following papers were read :— 
1. Notes on the Hair-Slope of four Typical Mammals. 
By Wauter Kipp, F.Z.S. 
[Received November 27, 1902.] 
The Otter, Domestic Dog, Ox, and Horse have been selected 
for consideration as showing very different arrangements of their 
hairy coverings, and as affording by their environments and habits 
the probable explanation of the differences found. Two Carnivores 
and two Ungulates are thus compared and contrasted. 
(1) In the Otter, taken as a type of the long-bodied hairy 
mammal with very short limbs, the hair presents an unbroken 
slope from the snout to the tip of the tail, On the head and 
