the Mouth in Sucking Crustacea. 11 



the cljpeus and the base of the posterior antennae, so that the 

 small terminal joint projects between the antennse. Both pairs 

 of maxilla are small, completely covered hj the large and flat 

 maxillipeds. The first pair of maxillas exhibit only one 

 narrow lobe (the middle lobe), which is armed at its apex with 

 a few fine spines. The second pair of maxillge have three 

 small, narrow, and inarticulate lobules, of which the middle one 

 and the external one or palpus are moveable. The cardo of 

 the maxillipeds (fig. 2, ^:»a?) is very large, transversely placed, 

 and divided by membranaceous seams into several plates ; the 

 stem is small and short, but has a large foliaceous prolongation 

 on the outer side, whereby the base of the stem becomes as 

 broad as the anterior margin of the cardo, so as to produce the 

 impression that the cardo here lies behind the stem, whereas 

 it really lies, as usual, obliquely outside it ; the short adnate 

 lobes form in connexion with the stem a thick crest on the 

 upperside, which is made to fit alongside a ridge, which on 

 either side marks the outline of the broad sphenoid plate. 

 This latter is at the base carinate and at the apex deeply bifid. 

 The palpus is short, thick, biarticulate. 



If, now, the clipping and tearing mouth and active appear- 

 ance of Cirolance forcibly suggests the idea of a small shark, it 

 is difficult to contemplate the Serolides without thinking of a 

 little ray or skate. That they live near the bottom is suffi- 

 ciently evident from their broad, short, slightly vaulted general 

 form, the crested and carinated dark-coloured back, the smooth 

 white under surface,the sickle-shaped imbricate epimera, the flat 

 broad head which is closely li i ted into the first segment of the 

 body, the salient eyes placed on the upper surface of the head, 

 the position of the mouth on the under surface, and the limi- 

 ted capability of swimming. Besides, their mandibles, though 

 powerful, are not arranged cither for clipping, grinding, or mas- 

 ticating, but only Ibr pinching or squeezing and biting through 

 a hard surface ; the maxillipeds cover up the other, very 

 small, appendages of the mouth ; and after them follow two 

 pairs of prehensile limbs of the same kind as those of Mantis^ 

 Nepa, and Squilla. It cannot, therefore, be doubted that Sero- 

 lides live upon prey, and that this consists of small rather slow 

 animals living near the bottom, probably mostly such as have 

 firm integuments. The hypothesis suggested by Milne-Edwards 

 (Hist. Nat, des Crustaces, iii. 231), that they attach themselves 

 to fishes, is contradicted by the very feature of their structure 

 to which he refers in support of it. Their flat mouth would 

 be powerless against the skin of a fish, even if the cup-like 

 shape of the anterior parts of the body did not prevent the 

 mouth from reaching the skin. Furthermore, the first pair of 



