NEBALIAD.E. 33 



that the young are born in May, appear completely to 

 refute the opinion hazarded by Mr. Thompson, of Cork, 

 that they are most probably only the larvae of a Cirrhipede. 



Anatomy, Physiology, 8fc. In the Nebalia the cara- 

 pace is large, oval-shaped, and covers the whole of the 

 cephalo-thoracic portion of the body, and part also of the 

 abdomen. It is attached only to the head ; the thoracic 

 and abdominal segments being quite free and unattached. 

 It is not shield-shaped, as in the Apus, but descends upon 

 the sides, and incloses the portion of the body which it 

 covers, as in a bivalve shell ; the antennae, the natatory feet, 

 a portion of the abdomen, and the tail protruding beyond 

 it. In front, it terminates in a sharp-pointed rostrum or 

 beak, which is slightly curved downwards, and is move- 

 able. 



The eyes are two in number, and may be seen pro- 

 jecting from under the anterior edge of the carapace, 

 on each side of the base of the rostrum. They are of 

 considerable size, and of a brown colour, " appearing," 

 says Montagu, "in a strong light, crimson." They are 

 situate upon moveable peduncles, and are formed of a 

 transparent cornea, underneath which are a great number 

 of small crystalline bodies surrounded with a brownish 

 colouring matter. 



The antennae are two pairs, both of them large and 

 ramiform, so that they are fitted to serve for swim- 

 ming. The first pair are situate immediately below 

 the eyes. They consist of a basilar portion, composed 

 of two strong joints, from the second of which spring 

 an oval ciliated plate, and a slender stalk divided 

 into nine or ten articulations, each articulation having 

 two or three hairs issuing from its base. The second 

 pair spring immediately behind the preceding, and are 

 bent so as to be directed at first obliquely forwards, then 

 downwards and backwards. The basilar portion consists 

 of three stout joints, the last of which sends off a long 

 stalk of about ten articulations, considerably longer than 



3 



