Luminausness of the Sea, ^lf7 



given to them as a defence and protection, and to enable them 

 to take their prey in their deep and dark abodes in the 

 fathomless waters of the ocean, it is extremely probable that 

 it is given to the whole tribe of marine animals. Independently 

 of this, however, some of these little creatures are extremely 

 interesting, and, as little has been added to this order of 

 beings since the time of MuUer, figures and descriptions of 

 several new species, although these are perhaps rather imper- 

 fect, may still be worthy of notice ; and, even though they are 

 not sufficiently correct to entitle them to be classified and 

 named, it is possible they may assist future labourers in this 

 much neglected branch of natural history. 



One of these Entomostraca, which occurred several times 

 in company with those luminous animals already described 

 (Jig.Sl. ah c d\ and in considerable abundance when the 

 sea was most luminous, is figured v^ijig, 83. d. The head and 

 body are in one, flat, of an oval shape ; tail double, each por- 

 tion terminated by a fasciculus of fine hairs ; antennae two, 

 linear, armed with hairs or bristles on both sides, which 

 point forwards ; eyes two, situated laterally, and near the 

 upper part of the body. Near the lower extremity of the 

 body, close to the tail, were two dark substances projecting 

 outwards, most probably the ovaries. The body of the ani- 

 mal was quite transparent, and showed the viscera and the 

 red blood in motion ; natural size, a grain of sand. This little 

 animal bears a considerable resemblance to one of Muller's 

 figures, a species of Cyclops ; but as that genus is character- 

 ised as having only one eye, and as I made out distinctly two 

 in this specimen, I cannot, till another opportunity occurs of 

 farther examination, refer it to that genus. Two other little 

 •creatures, however, occurred, which I have no hesitation in 

 referring to the Cyclops of Muller. {Jig, 83. ^ and /) One or 

 two species have been ascertained, by Sir C. Giesecke in Green- 

 land, to be luminous, and Dr. Macculloch has added thirty- 

 three new species in our own seas, all of them highly luminous. 

 The first of these which I have represented {fig, 83. e) is an 

 exceedingly nimble little creature ; and, not being larger than 

 a pin's point, it required great attention to be able to follow 

 its movements. The body is of an oval shape, divided into 

 five segments ; antennae two, linear, covered with prickles or 

 hairs, and fully the length of the body ;, feet about five on each 

 side; tail double, each division terminated by a number of 

 fine hairs ; eye, one ; the round spots on the upper surface 

 of the body are ova. This species somewhat resembles the 

 C rubens of Muller (Entomostraca, tab. xvi. fig. 3.) ; it is, 

 however, a very distinct species. IPig, 83.y is also a Cyclops, 



Y 3 



