574 Dr. It. von Willemoes-Suhm on Observations 



and it is not uninteresting to find that Balanus, a crustacean which was 

 eminently developed in the Tertiary formation, is now nearly entirely 

 confined to shallower water, but that the Lepadid Scalpellum, which is 

 mostly found in the Cretaceous formation, is now-a-days widely spread 

 in the greater depths. Indeed it has been the only Cirriped which we 

 have often met in depths from 925 to 2850 fathoms, and was got in the 

 Atlantic six times, one of them having been described by Professor Wyville 

 Thomson under the name of Scalpelliim regium (< Nature,' 1873). 



Of free-living Copepods there are none on our list, nor do I think 

 that any are living below the range of the so-called surface-animals ; but 

 their parasitical relations are found as well on the deep-sea fishes as on 

 those from shallower water — as, for example, on a Lophioid allied to 

 Ceratias, which came up from a depth of 2400 fathoms, and is sure, from 

 Ihe mode of living peculiar to that group of fish, to have come from the 

 bottom. 



There are no Ostraeoda to be mentioned here ; and of Amphipoda (which, 

 however, are by no means wanting in deep water) only one specimen of 

 Eusirus cusjpidatus has been put down by me ; but perhaps some more 

 might be found among the siftings. 



Very peculiar are the deep-sea Isopods ; for besides the ordinary Arctu- 

 rus-iorm which we got from 450 fathoms, there is a very peculiar family 

 of which Sars has described five genera from the Norwegian coast, all of 

 which are blind. The body is divided into two portions ; the anterior one, 

 consisting of a head with four segments of the pereion, is short, and the 

 posterior, consisting of the three remaining pereion-segments, rather 

 long. The first pair of legs is short and prehensile ; but the three follow- 

 ing pairs have an extraordinary length, and are very thin and slender, 

 and the last three pairs are terminated by paddle-shaped joints and act 

 as natatory organs. Very peculiar is also their abdomen, which consists 

 of only one segment, on the end of which we find two small setigerous 

 papillae. Of these Munopsidae, the legs of which break unfortunately 

 very easily, we got a large and very soft species from 2175 fathoms on 

 our passage from Bermudas to the Azores, and another spiny species 

 not far from there from 1675 fathoms. 



"When dredging off the coast of Brazil near Pernambuco we fell in for 

 the first time with an Isopod, which, from a superficial resemblance with 

 the fossil Trilobites, has enjoyed for some time a certain notoriety ; I mean 

 tSerolis, the flat crustacean which has long been known as inhabiting the 

 southern coast of America. We never found it again in the tropics, 

 neither in deep nor in shallower water, but shall have to mention it fre- 

 quently among the Crustacea of the Antarctic. 



A blind Tanais was brought up from 1400 fathoms. 

 Cuma, which, according to Claus, has its nearest relations among the 

 Isopods, is not common in deep water, and was found only once in 1000 

 fathoms near San Miguel, Azores. 



