180 BRITISH PARASITIC COPEPODA. 



Family vn. LERN^OPODID.I:. 



Female. Body in the adult female usually non- 

 segmented or indistinctly or incompletely so. Head 

 small, thorax not clearly denned, Harrow and more or 

 less elongated, but sometimes short as in Lern&opoda 

 chdlise. Abdomen usually separated from the thorax 

 by a constriction tolerably distinct but seldom if ever 

 forming a complete articulation ; the genital segment 

 of the abdomen usually enlarged and sometimes pro- 

 vided with posterior processes ; the remaining ab- 

 dominal segments usually obsolete or rudimentary. 

 Appendages of the cephalon and thorax comprising 

 antennules and antenna, mandibles, maxillae, and first 

 and second maxillipeds, but the thoracic usually obso- 

 lete or entirely wanting. The second maxillipeds arm- 

 like appendages elongated or short, and modified to 

 form organs of attachment, the arms entirely separated 

 except at the tip or partly or completely coalescent ; 

 united at the distal extremity to a chitinous process 

 which penetrates the tissues of the host, and the 

 character of which may vary in the different species. 

 Egg-strings generally only moderately elongated and 

 the ova small and arranged in a multiseriate manner. 



Male. Very small and furnished with several ap- 

 pendages the structure of which is more or less rudi- 

 mentary. Its form varies in the different genera, 

 and it is usually found adhering to some part of the 

 female i.e., the rudimentary abdominal segment or 

 the cephalothorax. 



Milne Edwards included Anchorella (Clavella) in his Family 

 Lerneopodiens, but Dr. Baird removed this genus and estab- 

 lished the Family Anchorellidse for its reception. The dif- 

 ference between Lern&opnda and Anchorella is obvious in two 

 particulars in the structure and modification of the second 

 maxillijK'ds and in the form of the pygmy male. The first 

 provided Baird with the principal character by which the 

 two Families could be distinguished, and might have been 

 considered valid except for the occurrence of genera inter- 

 mediate in structure, which made it more convenient to include 

 them all under the one Family Lerna3Opodidae. 



