S. I. S/tr/'f/i — Earl;/ Stages of Hippa talpolda. 310 



the first specimen and as in tlio succeeding stages. This is appar- 

 ently an abnormal variation in the armament of the telson. The 

 arrangement of these spines, and especially whether they be odd or 

 even in number, I have usually found a constant character for distin- 

 guishing the larval forms in different groups of Podophthalmia. 



Of this stage only two specimens Avere secured, one taken on the 

 evening of September 4, the other in the day-time the next day. In 

 coloration and habits they agreed essentially with the young in the 

 succeeding zoea-stages. 



Third zoea-stage. 



In general form and a]»]K'arance the zoeas in this stage very 

 closely resemble those in the second, although they have increased 

 considerably in size, and especially in the length of the rostrum, 

 which is relatively longer and more slender. They are about 4"5""" 

 in length, from the ti]) of the rostrum to the posterior mai'gin of the 

 cara})ax, and nearly :V""' between the tips of the lateral spines. 



The ocular peduncles and eyes have increased only slightly in abso- 

 lute size and are relatively smaller than in the second stage. 



The antennuhe liave changed very little. There is, as yet, appar- 

 ently no distinction of peduncle and fiagellum, although the two or 

 three distal segments of the latter are faintly indicated, and, on the 

 inner side, there are two or three filiform setae on tlie penultimate 

 segment in addition to the three on the terminal segment. 



The antennae (Plate XLVI, fig. ;3) have increased in size but show 

 no indication of segmentation. The two dentiform processes (a, ft, 

 fig. 3) have each two or three minute spir.ules at the tip, but are 

 otherwise unchanged ; the fiagelluin (c, fig. 3), however, has increased 

 so as to project beyond the tips of the dentiform processes and show 

 ))laiiily its true character. 



The labrum, labium, mandibles, and first maxillse, excej)t in size, 

 do not differ appreciably from their condition in the second stage. 

 The second maxillae differ but little, the scaphognath being a little 

 more elongated posteriorly, so as to approach slightly its form in the 

 next stage. 



The first and second pairs of maxillipeds differ from those of the 

 first stage only in the exognaths, which are each furnished with ten 

 instead of eight terminal seta'. 



The lobes representing the third pair of maxillipeds and the four 

 anterior pairs of thoracic legs have increased much in size, are 



Trans. Conn. Acad., Vol. III. 41 April, 1877. 



