ON THE SHETLAND CRUSTACEA, TUNICATA, ETC. 251 



the determination of the species rests upon the authority of the naturalist 

 whose name follows the quotation. 



1861. Mr. Jeffreys, Mr. Waller, and myself. The dredging this year was 

 chiefly carried on from the Whalsey Skerries, where the Lighthouse was 

 made our headquarters ; but a short cruise was taken, just before the home- 

 ward voyage, to the ground to the north of Unst, which in later years 

 proved so productive. Yessel, the yacht ' Osprey.' 



1862. Mr. Jeffreys and Professor Allman. The expedition came to a pre- 

 mature and unfortunate termination. The vessel which had been chartered, 

 having been caught in a heavy gale at sea, had her rudder-post carried 

 away, and thus became disabled. Professor Allman, however, succeeded in 

 procuring several Hydrozoa new to science. 



1863. Mr. Jeffreys, Mr. Waller, Mr. R. Dawson, and myself. A steamer 

 was this year engaged in the work, and the dredging was in the directions 

 north, north-east, and east of IJnst. 



1864. Mr. Jeffreys, Mr. Waller, and Mr. Peach. The dredging was chiefly 

 carried on to the north of Unst, Balta Sound being made the headquarters 

 during the greater portion of the summer. Mr. Peach paid special attention 

 to the sponges, and discovered several new species. Vessel, the ' Osprey.' 



1867. Mr. Jeffreys, Mr. Waller, Mr. Dodd, and myself. The bed of the 

 ocean, to the north and west of Shetland, was investigated, and at greater 

 depths than had before been tried. A fortnight was also spent in examin- 

 ing the rich fauna of the deeper parts of St. Magnus Bay. Yessel, Mr. 

 Jeffreys's yacht the ' Osprey.' 



1868. Mr. Jeffreys, Mr. Waller, and Major Woodall. Dredging chiefly 

 to the north of Unst and St. Magnus Bay, but the Out Skerries Haaf was 

 also visited. Vessel, the ' Osprey/ 



My sincere thanks are especially due to my kind and valued friends Mr. 

 Jeffreys and Mr. Waller, for the assistance they rendered me in all kinds of 

 ways during our dredging operations, and in the preservation of those inver- 

 tebrata which it is my duty here to notice. 



In 1867 Mr. D. Bobertson went to Shetland, and, besides dredging and 

 using the towing-net in Bressay Sound, he visited many of the inland lochs 

 and streams, for the purpose of examining the Crustacea which they might 

 contain. I have to thank him for having kindly allowed me to examine 

 the gatherings which he made, and I am thus enabled to add many species 

 to the list of Entomostraca. 



In the preparation of the Tables which follow, it must be understood 

 that I have not relied solely on published localities. A large number of the 

 species have been identified by myself from habitats further to the north or 

 to the south than those which have been recorded in print. This will 

 account for the absence of many names from the Tables IV., V., and VII. 

 which might have been expected there. 



I. 



Comparison of the Total Number of British and of Shetland Species. 

 The following Table is intended to show 



1. The number of species belonging to the several Classes and Orders, as 

 given in the " List of the British Marine Invertebrate Fauna," published by 

 the British Association in 1861, and which supplies us with a carefully cor- 

 rected catalogue of the species known seven years ago. 



2. The total number of species which have been recorded as British up to 

 the time of publication of this Eeport. This estimate I have drawn up 



