THE AMPHIPODA 



225 



Synopidea, Bovallius, and Subhyperini, Delia Valle, and still less 

 reason for the inclusion of the Tanaidacea, advocated by Gerstaecker. 

 On the other hand, the very remarkable genus Ingolfiella, Hansen, 

 may conveniently, for the present, be kept apart in the sub-order 

 Ingolfiellina which Hansen has established for it. Among the more 

 important contributions to our knowledge of the group mentioned in 

 the list of literature at the end of this chapter, attention may be 

 called to Spence Bate's British Museum Catalogue, Spence Bate and 

 Westwood's Monograph of the British species, and to the works of 

 Boeck, Bovallius, Glaus, and Delage. As with so many other 

 groups of Crustacea, the memoirs by G. O. Sars are numerous and 



VH1. 



ex. 



I . 



6. 



C. 



ace. 



FIG. 13-2. 



Gammarus locusta, <5 , from the side, x 4. a', antonnule ; a", antenna ; ace, accessory (iuner) 

 flagellum of antennule ; br, branchia ; ex, coxal plate ; gn, gnathopods ; pip'", pleopod of 

 third pair ; prp', prp", first and second peraeopods (fourth and fifth thoracic appendages) ; 

 e, telson; ur, uropod (sixth abdominal appendage); II, VIII, second and" eighth thoracic 

 somites ; 1, 6, first and sixth abdominal somites. (After G. O. Sars.) 



of the first importance. Delia Valle's Monograph is valuable for 

 anatomical and biological details, but the systematic part of the 

 work is to be used with caution. The bibliographical history of 

 the Order has been given at length in the admirable Introduction 

 to Stebbing's Report on the " Challenger " collection, and the same 

 author has recently completed a masterly revision of the Gam- 

 maridea for the Tierreich. P. Mayer's Monograph and his later 

 memoirs on the Caprellidea will not soon be superseded as the chief 

 sources of information on that sub-order. 



MORPHOLOGY. 



The body of a typical Amphipod, such as Gammarus (Fig. 132), 

 is laterally compressed, with the abdomen of considerable size and 



