196 Prof. C. Mobius on the MoUusca &c. of the 



XXIX. — MoUusca^ Vermes^ and Coelenterata of the Second 

 German North-Polar Voyage. By Cael Mobius *. 



[Plate XI. figs. 4-14.] 



The region in which the invertebrate marine animals cited in 

 the following Catalogue were collected by Dr. Pansch, between 

 the shore line and a depth of 30 fathoms, extends from 73° 50' 

 to 75° 15' N. lat. Here the animals live in a temperature which 

 varies but little throughout the year. According to the log- 

 book of the ^ Germania,' Captain Koldeway, the daily average 

 of the surface-temperature from the 9th of July to the 13th of 

 September 1869, from 70° 44' to 75° 30' N. lat., only oscillated 

 between l°-62 and l°-29 R. ( =35°'64 and 34°-9 F.).' Then ice 

 was produced, beneath which, from the 3rd of October 1869 to 

 the 21st of May 1870, a temperature of l°-5-2° R. (=35°-4 

 -36°*5 F.) prevailed. Measurements of temperature down to 

 220 fathoms within the same latitudes between the 13th of 

 July and the 3rd of August 1869 gave 0°-4-l°-3 R. 

 ( = 32°-9-34°-92F.). 



In the year 1870 the surface temperature between 71° 20' 

 and 75° 26' N. lat. from the 11th of July to the 28th of 

 Septemberwas found to be 0°-02-4°-62 R. ( = 32°-045-42°'4 F.). 

 Between 73° 11' and 71° 30' from the 12th of August to the 

 27th of September, at depths of 20-300 fathoms, 0°-7-2°-6 R. 

 ( = 33°-57-37°-85F.) were observed. 



According to the log-book of the ' Hansa,' Captain Hege- 

 mann, l°-0°-6 R. (=34°-25-33°-35 F.) were found at 20-75 

 fathoms, on the 14th and 15th of July, in N. lat. 74° 37' and 

 74° 57' ; and 1° R. (34°-25 F.) at 100 fathoms in N. lat. 73° 5'. 



In his address upon the scientific results of the first German 

 North-Polar voyage of 1868, M. von Freeden says (p. 4) : — 

 " Beyond the parallel of Jan Mayen (71° N. lat.) as far as 77° 

 we find a great sea-surface which, from the 1st of June to the 

 1st of September, possesses a temperature oscillating between 

 0° and 2° R. ( = 32° and 36°-5 F.), and which is more and more 

 filled with melting masses of ice tlie further west we go." 



Thus^ with regard to the oscillations of temperature in their 

 medium^ the marine animals of Greenland are in just as favour- 

 able a position as the animals of the tropical seas. 



According to Dana's ' Classification and Geographical Distri- 

 bution of the Crustacea,' 1853, p. 1483, the mean surface- 

 temperatures of the thirty coldest and the thirty warmest con- 

 secutive days are as follows : — near 



* Translated and abridged by W. S. Dallas, F.L.S., from the Report 

 of the Voyage, vol. ii. 1873, pp. 24G-261. 



