of the French Coasts. 163 



adults. The abdomen, antennae, and feet exactly resemble those 

 of the adults. 



At its first escaping from the egg the body of the young ani- 

 mal is perfectly cylindrical. The antennae are broad, flat, and 

 rounded at the end; their joints are not distinctly marked. The 

 first legs are very strong, and composed of four joints, terminated 

 by a stout claw ; then follows a pair, thinner, of footjaws, ter- 

 minated by bristles or spines, and beneath these is the rostrum, 

 formed of two pairs of jaws ; beneath these is another pair of 

 short, slender feet, placed laterally, followed by another larger 

 pair, curved upwards, and furnished with a comb of strong 

 spines or rigid hairs. The thoracic feet are already biramose. 



Notopterophorm Bomhyx, Hesse. 



This Crustacean, found in the interior of Phallusia intestinalis, 

 is doubtfully described as a new species by the author. The 

 male, as in the preceding species, is one-third of the size of the 

 female. Its head is much larger ; the thorax is broad and short, 

 and diminishes gradually in diameter to the abdomen ; it is very 

 retractile, the segments forming it have their margins everted 

 so as to favour their invagination, and the lower extremity of 

 the last segment, being capable of vertical elevation, forms a sort 

 of broad, flat surface, which probably serves as a point of sup- 

 port for propulsion. 



The membranous dorsal expansions appear to be much less 

 extensive than in N. papilio, and that which is implanted upon 

 the nape presents at its base an occipital protuberance. The 

 colour is entirely yellowish white. 



The female is elongated, especially in the abdominal region j 

 the head is also very long, and the ridge which forms the base 

 of the occipital membranous expansion is much thicker than in 

 the other species ; the membranous expansions are also smaller 

 and thicker. The antennae and feet are more slender, and the 

 last thoracic segment, which contains the eggs, is remarkable 

 for a peculiar structure which, when seen in profile, presents 

 some analogy with that of Doropygus. The female is very little 

 smaller than that of N. papilio ; its colour is pale yellow, with a 

 rusty red streak in the middle. The eye is red. The eggs are 

 very dark green, with a transparent limb. 



In this species the membranous expansions were more lace- 

 rated than in the other. The Crustaceans are seen constantly 

 extending and contracting themselves as if endeavouring to re- 

 move something, or to force a passage through resisting objects; 

 their movements of propulsion are aided by the strong claws 

 and spines with which the feet are armed, and the hooks which 

 terminate the abdominal appendages enable them to move back- 



12* 



