REPORT ON THE CRUSTACEA MA CRURA. 449 



three new species, but from comparison with those I have figured I am convinced that 

 they are only immature forms of the already known species. 



Professor Brooks 1 says : — "We found a few adult specimens out at sea, but, while I was 

 able to learn little about their habits, I think that they are not strictly pelagic, but that 

 their proper home is the salt marshes close to the ocean. 



" They were met with in the greatest abundance about half a mile inside Old Topsail 

 Inlet, near a large marsh, during the first hour of the ebb tide, on calm evenings when 

 the tide turned between 7 and 8 p.m.; and I infer that they leave the marshes at this 

 time to breed in the ocean. All the mature females which we found, with one exception, 

 were captured under these peculiar conditions ; and we never failed to find them at this 

 spot when the tide turned about sunset and the water was calm." 



Development of Lucifer. 



The interest in the study of this genus has been maintained ever since its first 

 discovery was made by Vaughan Thompson. This has been largely owing to the 

 anomalous appearance of the animal, arising chiefly from the enormous longitudinal 

 development of the regions between the anterior lip and the second pair of antennae ; the 

 reduction of the pereiopoda to three pairs, and the greater comparative development of 

 the pleon and its appendages, herein exhibiting features the very opposite to those of 

 the aberrant Amphipoda, where the pereion is increased in proportion and the pleon 

 reduced to a rudimentary condition. 



The difficulty of studying the history of the animal has been increased by the fact 

 that the female does not carry the ova attached to the pleopoda, as among the Prawns, 

 or in an ovisac as in other Crustacea. No one before Professor W. K. Brooks, 2 so far as 

 I am aware, ever observed the female bearing ova at all, and he found them in the 

 anomalous condition of being attached to the posterior pair of pereiopoda instead of to 

 the pleopods, and they appear to be retained in position by some adhesive property of the 

 ovum instead of being linked together like a bunch of grapes by a tissue developed for 

 the purpose. According to Professor Brooks the deposition of the ova takes place 

 between nine and ten in the evening and occupies only a few minutes. After deposition, 

 they are spherical, transparent, and have rather a thick case, and are loosely attached 

 in a bunch of about twenty to the third or posterior existing pair of pereiopoda, and so 

 feeble is their attachment, that " even when great numbers of mature specimens are 

 captured in the breeding season, with the greatest care and delicacy, very few of them, 

 much less than one per cent., are found to have eggs attached to their limbs." About 

 thirty hours after oviposition, the ocellus and appendages of the embryo become visible 

 inside the outer envelope, and after thirty-six hours the brephalos is hatched in the 



1 Loc. cit., p. 60. i Loc. cit., p. 64. 



(ZOOL. CHALL. EXP. — PAET LII. — 1887.) Fff 57 



