PARASITES UPON PARASITES. 



641 



Fig. A represents the PERCH-SUCKER, and fig. B the male of the same species. The 

 reader will notice the strange formation of the female, and the great dissimilarity between 

 herself and her small mate. Fig. C exhibit an 

 example of a curious genus termed Anchorella, 

 in which the arm-like appendages are very short, 

 and united from the base so as to look like a 

 single organ. At fig. C is seen the female Ancho- 

 rella uncinata. In this species the body is white 

 and the short arms end in a rounded knob. This 

 creature is rather more than half an inch in 

 length. At fig. D is shown the male of the same 

 species, which would hardly be recognized as hav- 

 ing 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 in length. 

 At fig. E is another species of the same genus, 

 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 creatures 

 infest the cod, haddock, and similar fishes. 



A wonderful example of a parasitic crustacean 

 in several stages of development is seen at figs. 

 H, I, K. This is the Tracheliastes, with its long 

 egg-bags and strangely developed upper extremity. 

 At fig. I is seen the same creature when very 

 young, and at fig. K it is again shown, though of 

 larger size. 



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. Two curious forms are 

 shown at figs. L and M. The former represents 

 the female of Lamproglena pulehella, and is given 

 in order to show the under surface of the body 

 and the small pairs of feet. These feet show that 

 it belongs to the family of the Penellada;. Fig. 

 M represents the Lernentoma asellina. This is 

 also a female. 



TURNING to the next engraving, we shall find 

 some more examples of these strange beings. 

 Not the least strange is that which is shown at 

 fig. A, inasmuch as it is parasitical upon a para- 

 site. This is the Chalimus scombri, which is 

 found adhering to a caligus. At fig. A a much 

 magnified drawing is given, showing the long 

 tube and sucker whereby it adheres to its prey, 

 and at fig. B the creature is 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 infaittum." 



4 1 



A. Actheres percarum. (Female. 



B. Actheres percarum. (Male.) 



C. Anchorella uncin&ta. (Female.) 



D. Anchorella uncinata. (Male.) 



E. Anchorella rugosa. (Female.) 



F. Lernentoma cornuta. (Female.) 



G. Lernentoma cornuta. (Male.) 



H. Tracheliastes polycolpus. (Female.) 

 I, K. Tr&cheliastes polycolpus. (Young.) 

 L. Lamproglena pulchella. (Female.) 

 M. Lernentoma asellina, (Female.) 



