i8g 3 . NOTES AND COMMENTS. 163 



head-shield is arched slightly upwards, apparently to afford space for 

 their play to and fro. On the side of the same head there are also 

 some impressions that may indicate the gills, though it is equally 

 probable they are merely hairs on a narrow limb, serving as mouth- 

 organs. 



Trilobites are also discussed in the same journal (pp. 142-147, 

 pi. ii.) by Dr. C. E. Beecher, who follows the work of Barrande in 

 attempting to interpret the larvae. Here, again, the fine character of 

 the sediments in which the fossils are embedded (Lower Helderberg, 

 near Albany, N.Y.) favours the investigation. Moreover, the facts 

 are of especial interest in this case, because all the trilobites belong to 

 highly ornamented and specialised genera. Some beautiful figures are 

 given with detailed descriptions, and Dr. Beecher concludes by trying to 

 generalise in reference to the normal life-history of a trilobite. The 

 results are too technical for recapitulation here, but they show that 

 before long zoologists will be able much more satisfactorily than 

 hitherto to discuss the reference of these characteristic Palaeozoic 

 organisms to Crustacea or Arachnids. 



Fishes at High Temperatures. 



Dr. Lawrence Hamilton forwards some interesting statistics he 

 has collected in reference to the existence of fishes in water of a high 

 temperature. Some of the cases are very striking. Spallanzani, it 

 appears, observed river carp living at a temperature of 106 F., and 

 exhibiting no signs of uneasiness, though at 109° they began to 

 struggle, and died at u6°F. Dr. John Davy (1835) showed that 

 the Bonito had a temperature of 99°, while the water of the Mediter- 

 ranean, in which it was, had only a temperature of 8o°. Saussure stated 

 that he found eels in the hot springs of Aise, in Savoy, at a tempera- 

 ture of 113 F. In 1882, Dr. Davy found that water at 85 F. killed 

 trout by convulsions. A trout and a minnow were put in water at 

 70 at night, which by the next morning had sunk to 67 , when the 

 trout was dead, though the minnow had not suffered. A salmon parr 

 at 8o° became convulsed and torpid, dying at 84 . Several fishes were 

 deposited in water at 53 F. ; the temperature of the water was 

 gradually raised, and none showed signs of failing vitality till the 

 thermometer rose to 82 , when the perch became prostrated, roach 

 succumbed at 82^°, salmon at 83 , minnow at 85 , gudgeon at 85^°, 

 dace at 86°, tench at 88°, and carp at 91 . Brandy restored all the 

 fishes except the dace, which died. 



In India, fishes at noon-day in their natural water remain in 

 health at 92 ; at 4 p.m., 86° ; and at 6 p.m., 82 . Gunther states that 

 Cyprinodonts live in briny springs even at a temperature of 91 F. 



Sir Emerson Tennent collected the following observations, which 

 seem to require further proof or verification : — 



In the hot springs of Ceylon, living carp, Nuvia theymoicus, at 



