REPORT ON THE AMPHIPODA. 1441 



Primno macropa, Guerin (PI. CLXXVIIL). 



1836. Primno macropa, Guerin, Magasin ile Zoologie, t. vi. Classe vii. p. 4, pi. xvii. figs, \a-\f. 



1838. „ „ Milne-Edwards, Hist. Nat. des Anim. sans vertebres, t. v. 



1840. „ „ Lucas, Hist. Nat. des Crust., Arachn. et Myriap., p. 239, pi. xviii. 



fig. 7. 

 1S40. „ „ Milne-Edwards, Hist. Nat. des Crust., t. iii. p. 81. 



1849. „ macropo, Nicolet, Hist. fis. y pol. de Chile por Claudio Gay, Zool., t. iii. 

 1862. ,, macropa, Spence Bate, Brit. Mus. Catal. Amph. Crust., p. 322, pi. li. fig. 8. 

 1884. „ „ Gerstaecker, Bronn's Klasseu und Ordnungen, Bd. v. Abth. ii. Taf. 



xxxv. figs. 3, 3<v. 

 1S87. „ ,, Bovallius, Systematical List of Amph. Hyper., Bihang till K. Svensk. 



Vetensk.-Akad. Handl., Bd. 11, No. 16, p. 28. 



Head irregularly globose, when detached together with the mouth organs having 

 in a front view a sort of balloon-shape, the rostral angle above the upper antenna? 

 rounded, folded inwards ; the first segment of the peragon very narrow below, but 

 dorsally the longest of the perseon-segrnents except the seventh ; the seventh perseon- 

 segment and the two first of the pleon produced backwards into sharp processes in the 

 middle of the back ; the peraeon not carinate, but tending to be so, especially at the last 

 segment ; the first three segments of the pleon not very strongly carinate, the postero- 

 lateral angles of the first two squared, of the third very acute, the fourth segment longer 

 than the coalesced fifth and sixth. 



Eyes covering most of the surface of the head, the upper and lower eye on each 

 side of the head contiguous, but the upper having much larger ocelli than the lower. 



Upper Antennse. — The peduncle consisting of one joint, which is short and stout, 

 cylindrical, widening distally; the flagellum also consisting of one joint, which is long, 

 prismatic in section, tapering at first rapidly, with five short filaments on either side, 

 beyond these becoming very narrow, and drawn out to a fine point. 



Lower Antennse wanting in the female, or only represented by a small pro- 

 tuberance. 



Mandibles. — The cutting edge narrow, minutely striated, with a little tooth at either 

 end ; a small group of spiuules adjoins the tooth of the lower end ; the secondary plate of 

 the left mandible is very small ; the molar tubercle broad, its crown fringed with com- 

 paratively long teeth and set with numerous hair-like spines ; behind the molar tubercle 

 the lower edge forms a very convex lobe ; there is no palp (in the female). 



Lower Lip short and compact. 



First Maxillie. — The plate narrows to the distal margin, on which it carries three 

 comparatively large spines and a smaller one at the outer corner ; six small ones fringe 

 the inner margin, having below them four or five that are almost thread-like ; the one- 

 jointed palp reaches beyond the plate, is very slightly curved, of almost even breadth 



(zool. chall. exp.— part lxvii.— 1888.) Xxx 181 



