646 CLASS x. 



Calymene BKONGN., Homalonotus KOENIG, Asaphus BliONGNj 

 (Add some other genera omitted here). 



Sp. Calymene Blumeribacliii BRONGN., TORRUBIA Apparato para la Historic^ 

 natural Espanola, Madrid, 1754, fol. Tab. in. fig. 4, p. 83 ; BLI 

 BACH Abb. naturJiistor. Gegenstdnde, No. 50, DALM. 1. 1. Tab. i. figs, i, 3, 

 a-c, c. 



Note. On these and some other genera, more numerous than 

 seems to be necessary, consult the authors quoted ; on Battus DALM. 

 see especially BEYRICH, i. s. 44. Other genera, Eurypterus DEKAY, 

 Cytherina HISTNGER, seem scarcely to have their place here. 



ORDER VII. Isopoda. 



Head distinct from the segment bearing the first pair of feet. 

 Trunk divided into seven rings sustaining seven pairs of feet. 

 Feet of trunk all undivided. Tail with segments different in 

 number up to seven, supplied beneath with branchial foliaceous 

 feet. Mandibles and maxillae mostly distinct. Antennas four, the 

 lateral at least setaceous. Eyes two, sessile, in most composed of 

 a cluster of ocelli, in others compound. 



Family XIV. Epicarides or Bopyrina. Antennas very short, 

 imperfect, resembling tentacles. Feet short, incurved, hooked. 

 Parasitic animalcules ; females much larger than males, broad, with 

 eyes none or indistinct. 



Bopyrus LATR. Five pairs of abdominal feet lamellose, con- 

 cealed under abdomen. 



Compare H. RATHKE, De Bopyro et Nereide commentationes anatomico- 

 physiologicce du<z. Cum tab. iii ceneis. Rigse et Dorpati, 1737, 4to. 



The species hitherto known of this and the following genus live parasiti- 

 cally on Palcemones (Carides), in the gill-cavfty or on the ventral surface of 

 these crustaceans (Bopyrus abdominalis KROEYER on Hippolyte). The sexual 

 difference is in these animals when adult very great. The male is elongate, 

 narrow, and keeps himself hidden between the gill-plates of the female. 

 The female is much larger, broader and asymmetrical. There are seven 

 pairs of short feet attached to the trunk, and five pairs of gill-leaves (abdo- 

 minal feet) on the abdomen, which is divided into six rings, of which the 

 hindmost is very small, and bears no gills. The young animals of each 

 sex are on the contrary of similar form, with four pairs of feet and long 

 posterior antennae (RATHKE, Zur Morphologic, Reisebemerkunycn aw 

 Taurien, s. 47 51). 



