338 iS. I. Siiiith — Early Stages of Wppa talpoida. 



is evidently the terminal portion of the inner lobe of the first maxilla 

 (Plate XL VII, fig. 10, a) ; but its " palpus composed of two small, 

 lamellar segments " is not so easily interpreted, though it may 

 possibly be the real mandible itself. In the figures of Remipes testii- 

 dinurius given in Milne-Edwards' volume on the Crustacea in the 

 third edition of Le Kegne animal de Cuvier, figure 1'', plate 42, is 

 simply the inner lobe of the first maxilla, which is entirely wanting 

 in the otherwise correct figure of the maxilla itself; but the only 

 alhision to the mandibular palpus is in the explanation of figure, " 1'', 

 Mandibules (ces organes sont depourvus d' appendice palpiforme)." 

 In Milne-Edwards' description of the genns Sippa (Histoire naturelle 

 des Crustaces, ii, p. 207) no reference is made to the maxilhe or man- 

 dibles, and no part of either of these appendages is given in the 

 figures of If. emerita in Le Regne animal de Cuvier. 



De Haan's figures of mouth appendages of Remipes (Fauna 

 Japonica, Plate Q) are like those of Milne Edwards just referred to, 

 except that he has left the basal portion of the inner lobe of the first 

 maxilla propei'ly attached in jslace to answer for the inner lobe which 

 he describes as the " lacina interna brevissima" (op. cit., p. 201). 

 De Haan however failed to find the mandibular palpus, for he dis- 

 tinctly says in the description of these maxillary mandibles, " palpis 

 nullis." In regard to Ilipjxi, De Haan seems to have been more 

 fortunate, for, in his description of the genus (op. cit., p. 201), after 

 correctly describing the maxillje, he says, " Mandibukc minutissimae, 

 cartilaginejB, corona Integra, palpis membranaceis triarticidaris." 

 His figure of the mandible of Hippa Asiatica (op. cit., plate Q ; 

 copied as figure 14, Plate XLVI, of the accompanying illustrations), 

 although evidently drawn from the real mandible, is apparently very 

 incorrect. 



The following descriptions and figures of the mandibles and max- 

 ilhe in Hippa and Remipes are taken from H. talpoida Say, and R. 

 Pacificus Dana. 



Hippa. — The form and position of the labrum, labium, and mandi- 

 bles, as seen from beneath, are shown in figure 10 on Plate XLVI. 

 The mouth is a narrow, longitudinal opening bounded, each side and 

 posteriorly, by a margin raised above the general surface of the 

 buccal area, and in front, by the labrum ('^, figure 10), Avhich projects 

 anteriorly as a triangular, laraelliform plate above the epistome, from 

 which, however, it is separated by a considerable space. Beneath 

 the labrum, the margin of the ejnstome is reflected and projects 

 forward each side into a slender, lamelliform process (h) tiijped with 



