118 



All the abdominal appendages are foliaceously biramous, and in all but the 

 first pair the endopodite has a short styliform lobe at base. No transverse 

 suture in the exopodite of the caudal fan. Eggs small and numerous. 



The branchize are eight on either side, there being, in addition to the five 

 large pleurobranchiae of the last five thoracic somites, and in addition to the 

 small but well-formed podobranch of the 2nd maxilliped, two branchiae attached 

 to the somite of the external maxillipeds, of these two, one is large and although 

 it appears to belong to the series of pleurobranchiae really is an arthrobranch, 

 while the other is small (and easily overlooked) and is a pleurobranch. The 

 formula is as follows : 



Total 1+2 ep. 1 6 = 8 + 2 ep. 



Synopsis of the Indian species of Aegeon. 



I. Marginal carina of carapace smooth : pleura of first 5 abdominal somites 



vertically produced and acute ... ... ... ... jE. affine, 



II. Marginal carina of carapace beaded : first 5 abdominal pleura vertically 



produced but with truncated tips ... ... ... ... JE. medium. 



69. Aegeon affine, n. sp. 



an Pontoearis pennata Bate, Chall. Maor. Crust., p. 499, pi. xoi. 



ILLUSTRATIONS OF THE ZOOLOGY OF THB INVESTIGATOR, CRUSTACEA, PLATE LI. FIGS. 3, 4. 



Rostrum triangular, bifid at tip usually, not reaching halfway along the 

 eyestalks, with a minute spine on either side at base. 



All 7 carinas of the carapace are salient, and all but the supra-marginal one 

 on either side are coarsely serrate. The lateral carina of each side ends in a 

 huge wing-like tooth, beneath which is the spine formed by the termination of 

 the branchiostegal margin. The non-serrate supra-marginal carina ends in a 

 little tooth, anteriorly. 



The abdominal terga, besides much transverse and oblique sculpturing, are 

 carinated longitudinally. The 1st, 5th and 6th terga, and the telson, have two 



