486 THE SHARK-SUCKER. 



the order of the Lerneadae, in which the month is formed for suction, and the limbs scarcely 

 visible. All these beings are parasitic upon fishes, and are often so deeply buried in the 

 tissues, that the whole body is concealed and only the egg-bearing tubes suffered to appear. 

 As is the case with many creatures, especially those that occupy a low place in the scale of 

 creation, the young enjoy a wider range than the parent, being able to roam about at will, and 

 not settling down to a motionless existence until they have attained maturity. 



LERNEADA. 



There seems to be no bound to the wondrous forms which these parasites assume, as may 

 be learned from the following example : the Ohondracanthus zei. It is called so because its 

 body is covered with cartilaginous spines or tubercles. The name is derived from two Greek 

 words, the former signifying cartilage and the second a thorn. This strange being is found 

 upon the gills of the John Dory. 



The two most extraordinary beings, which are called Lernceodiscus and Jacculina, were 

 discovered under the abdomen of a lobster. In both these creatures (which certainly seem to 

 belong to the Lerneans), the whole of the head becomes modified into a set of branching fibres, 

 much resembling the roots of a tree. There is no mouth whatever, all nourishment being 

 transmitted through these fibres. They are quite recent discoveries. 



Though our space is rapidly diminishing, we may still mention a few more of these 

 creatures. One of common occurrence is the Perch-sucker, in which exists a great dis- 

 similarity between the female and her small mate. Another species is termed Anchorella 

 undnata. In this parasite the arm-like appendages are very short, and united from the base 

 so as to look like a single organ. The body of the female Anchorella is white, and the short 

 arms end in a rounded knob. This creature is rather more than half an inch in length. The 

 male of the same species would hardly be recognized as having any connection with the 

 long-bodied creature that has just been described. The length of the male is about the 

 forty-eighth of an inch. Another species of the same genus is the Anchorella rugosa, so called 

 because the body is notched at the side. This creature is about the seventh of an inch in 

 length. All these creatines infest the cod, haddock, and similar fishes. 



A wonderful example of a parasitic crustacean is the Tracheliastes, with its long egg-bags 

 and strangely-developed upper extremity. 



In the next tribe of Entomostraca the head is kept buried in the tissues of the animal to 

 which the parasites cling, and are there held firmly by some horn-like processes that spring 

 from the back part of the head. They are, in fact, living spears, the barbed heads being sunk 

 into their prey. The two best-known members of this tribe are the Lamproglena pulchella 

 and the Lernentoma asellina. 



Not the least strange-looking among them is termed Chalimus scombri. It is, like many 

 others of its class, parasitical upon a parasite, and it is found adhering to the caligus. With 

 irs long tube and sucker it adheres to its prey, and it may often be seen hanging to the lower 

 part of the caligus like a fish at the end of a line. This is one of the many instances that 

 prove the truth of that quaint and far-seeing old saying, namely — 



" Big fleas and little fleas 



Have lesser fleas to bite 'em ; 

 The lesser fleas have smaller fleas, 

 And so, ad infinitum." 



A creature that is found upon the sun-fish, and adheres to the gills, is called Oecrops. It 

 is not always fixed to 1 his habitation, but floats about by thousands in the Mediterranean, 

 where it is preyed upon by many tishes. 



Our next example is the Shark-sucker, a species that is found adherent to the eyes of 

 the Arctic shark, and appears to blind it. The sharks to which this unpleasant appendage 

 was attached seemed to lie quite destitute of sight, and did not flinch in the least when a blow 



