THE BAFFIN'S BAY ARCTURUS. 



much more energetic than that of the caterpillar. Indeed all its motions strike one as 

 peculiarly full of vigor and energy. 



I have seen the large red species swim, throwing its body into a double curve like the 

 letter S, with the head bent down, and the hind limbs turned back, the body being in 

 an upright position. It was a most awkward attempt, and though there was much effort 

 there was little effect." 



THE last figure on the illustra- 

 tion, marked D, is the creature 

 that is popularly known by the 

 name of WHALE-LOUSE. All the 

 species of this genus are parasitic, 

 residing on the whale and dolphin. 

 Their hooked and diverging legs, 

 armed with their sharply curved 

 claws, enable them to cling so 

 tightly that not even the swift 

 movement through the water, or 

 the active exertions of the crea- 

 ture on which they reside, are 

 sufficient to shake them from 

 their hold. The different species 

 of Whale-louse seem to prefer 

 various parts of the body, one 

 species clinging to the head, an- 

 other to the side, and another to 

 the fin. They all burrow rather 

 deeply into the rough and thick 

 skin of these marine mammalia. 



Their bodies are flattened and 

 rather oval ; they have five pairs 

 of legs, all prehensile ; and on the 

 second and third joints of the tho- 

 rax, instead of legs there are long 

 appendages for respiration, which 

 usually are bent over the back. 



IN this illustration are several 

 of the Isopod Crustacea, the sig- 

 nification of which word has al- 

 ready been given. In all the Iso- 

 pods there is a great resemblance 

 to the common woodlouse, and 

 many of them might easily be 

 mistaken for those common and 

 destructive beings. The females 

 have large horny plates on their 

 legs, so formed as to produce a 

 large pouch under the thorax, wherein the eggs are contained. In many species some 

 of the rings of the abdomen are connected so as to resemble a single joint. 



The BAFFIN'S BAY ARCTURUS is shown at fig. A, and is one of the best developed of 

 the whole order. In all the species belonging to this genus the body is long, and the 

 first four pairs of legs are beautifully feathered at the ends. These cannot be used 

 for walking, the three last pairs of legs being devoted to this purpose. The long 

 antennas are used as organs of prehension, and with them the creature captures its 

 prey. The young are said to cling by their legs to the antennas of the parent. 



A. BAFFIN'S BAY ARCTURUS.-Arrturus BattlalL 

 C, D. SHRIMP-FIXER.- E, F. IONE. 



Bopyras crangorum. lone thoraclcus. 



B. FISH-LOUSE. Cymothoe oestrum. 



