58 MEMOIR III. 



Genus 3. 



Lucifer, Long-headed Shrimp. 



This singular and extraordinary type of the Shizopodae, 

 like Nocticula, conduces to the sparkling appearance of the 

 sea in the Tropical regions, the individual figured in the 

 plate having been taken in the Atlantic September 15th N. 

 Lat. ir56' W. Long. 32° 55' 



We percieve in this animal a form hithertd unknown 

 amongst the Crustacea, viz. linear or vermiform, the 

 corselet not being broader than the abdominal segments, 

 with its anterior portion lengthened out into a kind of neck 

 widening in a slight degree upwards, and bearing at its extre- 

 mity, the Eyes and Antennae with their appendages, while 

 the mouth is situated at a great distance under the breast. 



It shews no further relationship to the former Genera, 

 than in possessing, long, simple, ciliated thoracic members, 

 these seem however to be fewer in number, and although 

 the natatory divisions characteristic of the Shizopodje were 

 not observed, for the same reason as mentioned under 

 Nocticula, I have no doubt of their existence : the thorough 

 developement of the abdominal portion of the animal, of 

 the sub-abdominal fins and tail, discountenance the idea of 

 its being the larva of some known Crustaceous Genus. 



The whole of the animal is colourless and transparent, with 

 the exception of its intestinal canal, which from the opacity 

 of its contents could be traced from the thorax to the tail. 



Description of Lucifer. 



Corselet, linear, posteriorly compressed, anterior portion 

 lengthened out and truncated, with a short spine at the 

 outer angles. 



Abdominal portion, of six linear segments, the last 

 largest with two short aculei on each side. 



Tailoi five scales ; the outer ones oblong, obtuse, and ci- 

 liated; the intermediate scales taper,rathcr acute andciliatej 

 middle scale subulate and somewhat shorter than the rest. 



