FEMALE OR HERMAPHRODITE. 257 



Mandibles, narrow, produced, with three teeth; inferior 

 angle pectinated, as is sometimes the third tooth ; the 

 distance between the tips of the first and second teeth 

 equals that between the second tooth and the inferior 

 angle. 



Jfaxilla, extremely narrow, produced, without any 

 notch ; spinose edge exactly one third of the length of 

 the mandibles : beneath the two upper great spines there 

 are only three or four pair of spines ; on the convex 

 upper margin there are some minute tufts of the smallest 

 hairs. 



Outer Maxilla, rounded with the inner margins very 

 sparingly but continuously covered with bristles. I could 

 not ascertain whether the olfactory orifices were tubular. 



Cirri. — These consisted, in the one specimen, of merely 

 small fragments. The segments of the posterior cirri are 

 elongated, not protuberant, and support, I believe, five 

 pair of non-serrated spines, and an exterior row of very 

 minute spines : dorsal spines fine and long. Either the 

 second or third cirri, or probably both 5 are remarkable for 

 having the whole of one side of each segment covered 

 with irregular rows of long spines. Moreover, in the upper 

 segments of these same cirri, between each separate dorsal 

 tuft, there is placed one or two long bristles. The first 

 cirrus appears to have had very broad segments, and these 

 are singular from the spines in the dorsal rows, being ex- 

 tremely long. In some of the cirri, several of the basal 

 segments are soldered together. 



Caudal Appendages, lost. 



From the state of the specimen, it was quite impossible 

 to ascertain whether the individual here described was an 

 hermaphrodite or female ; from the analogy of its nearest 

 congener, 8. ornatum, the latter is the most probable ; but 

 the genus Ibla shows how the sexes may differ in the 

 most closelv-allied forms. 



Affinities. — From the hollows on the under sides of the 

 scuta, for the lodgment of the males ; from the umbones 

 of the scuta and of the carina being situated on the apices 



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