S. I. Smith — Earlj/ Star/es of Hippo talpoida. 325 



The form of the cara}):ix resembles tliat of the adult very closely, 

 but is broader in proportion, being u half longer than broad ; the 

 lobes of the frontal margin (Plate XLV, fig. 5) are more obtuse and 

 much broader; and the lateral lobes form the antero-lateral angles of 

 the carapax, instead of being separated from the angles by a trans- 

 verse portion, each side, nearly as long as the thickness of the 

 peduncles of the antennie, while the lateral margins of the carajsax 

 are more regular in outline and do not project downward so much 

 between the fii'St and fourth pairs of legs. 



The ocular peduncles are still very short and stout, though the 

 eyes have increased only a very little in absolute size since the last 

 zoea-stage. The cornea is a little elongated and occupies the lateral 

 portion of the tip of the peduncle ; its greater diameter is still about 

 a fourth of the horizontal diameter of the carapax and more than 

 half the length of the peduncle. 



The antennulae (Plate XLVIII, fig. 1) reach to the extremities of 

 the peduncles of the antennae and show a marked advance over the 

 previous stages. The segments of the peduncle are fully difierentiated 

 and the second segment {h, fig. 1) has already a marked prominence, 

 tipped with a few plumose hairs, in place of the elongation, so con- 

 spicuous upon the inferior side of the distal extremity of the same 

 segment in the adult (Plate XLVIII, fig. 3). The flagellum [d, fig. 1) 

 is composed of eight or nine short and stout segments, all, except one 

 or two of the most proximal, armed inferiorly with jjliimose, or pecti- 

 nate, setse. The secondary fiagellum (e, fig, 1) is represented by a 

 single, minute segment tipped with a plumose seta. 



The antennae (Plate XLV, fig. 5, and Plate XLVI, figs. 7, la) are 

 slightly longer than the carapax and have assumed all the important 

 features of the adult. The segments of the peduncle (Plate XLVI, 

 figs. 7. la) are fully diflTerentiated and essentially the same as in the 

 adult ; and they have the same peculiar structure adapted to folding 

 the antennte across in front of the mouth and within the external 

 maxillipeds. To aid in accomplishing this, there is a supplemental 

 segment or rod (/, figs. 7, 7«) on the outer side of the third segment — 

 and apparently a separately calcified part of it — which articulates 

 proximally just within the lateral spine of the second segment and 

 distally with the outer edge of the fourth segment, and is so separated, 

 by non-calcified, flexible integument, from the third segment itself, as 

 to move independently of it. When the antenna is extruded, this 

 supplemental I'od lies parallel with the outer margin of the third 

 segment, from which it is then separated by a considerable space of 



