788 CRUSTACEA. 



Among the figures by Rathke, in his Norwegian Fauna,* we find 

 the same conclusion sustained. The figure of a Bopyrid, called by 

 him Phryxus Hippolytes (fig. 3, PL 2), represents the male, with the 

 tfiree posterior pairs of legs thrown obliquely backward, and the four 

 anterior obliquely forward, with a wide interval between the two 

 series. In this case, the Amphipod character (supposing the figure to 

 be correct) is beyond dispute. This species, as Rathke states, appears 

 to be identical with the Bopyrus Hippolytes of Kroyer. The genus 

 lone much resembles Phryxus, especially in the males of the species. 



In the Bopyrid genus, Cepon of Duvernoy, the three posterior pairs 

 of appendages, both dorsal and ventral, differ in certain points from the 

 four pairs preceding, as represented in the figures. 



These facts appear to determine the true nature of the Bopyri, 

 showing that they are related most closely to Tanais, and through 

 this genus to the Jaerae, which also are partly parasitic species. But 

 there is another fact, proving even more strongly their Amphipod 

 affinities, which is, the occurrence in some species of thoracic bran- 

 chiae ; for these are the only species among all the so-called Isopoda 

 that have this prominently Amphipodan characteristic. We are, 

 therefore, fully authorized in arranging the Bopyridae with the Aniso- 

 poda. 



8. Lirwpe, Crossurus. — These genera, established by Rathke in 

 his Norwegian Fauna, are related both to the male Bopyri and Tanais, 

 but more closely to the latter. There is the same grouping of the 

 legs as in Tanais, the three posterior pairs being in one group, and 

 the two anterior pairs being chelate. The abdominal appendages are 

 elongated in Liriopef nearly as in the Amphipoda, and to this group 

 the genus is referred by Rathke. The legs of the three anterior pairs 

 are two-branched ; of the three posterior, simple. 



A related genus, named by the author Cryptothir,h&& thoracic legs 

 like those of Liriope, the two anterior pairs being chelate, and the 

 three posterior in one group apart from the preceding. The species 

 occurred as a parasite within a Creusia (barnacle) . 



The tribe Anisopoda hence embraces a considerable number of 

 known genera, and this number will no doubt be greatly increased ; for 



* Fauna Norwegens, pi. 1, 2. 



f The species described by Rathke was found as a parasite to a worm (Peltogaster 

 Payurty, found on the abdomen of Bernhardus utreblonyx. 



