CYCLOPOIDEA. 1Q25 



3. By the obsolescence (fig. 2) of the articulation a, and the last 

 segment becoming obsolete. 



There is a redaction to four segments : — 



By the obsolescence of a and b, and also, the last segment becoming 

 obsolete (figs. 1 A, 1 B, 1 C, 6, 7, 8, Plate 70). 



The front is often truncated or rounded without appendages below. 

 In other species it has a short beak, which is either obtuse, or acute 

 and simple, or furcate (figs. 9 a and 14 a, Pontellce; 10, Catopia; 11, 

 Euchceta). In others still, as the Setellae, there is a pair of small 

 moveable unjointed appendages (fig. 12) attached below to the front. 



Eyes. — The eyes are of three kinds : — 



1. A pair of simple internal eyes with spherical lenses. These are 

 the common kind in this group. They are either united on a single 

 spot of pigment, which appears like a mere point unless highly magni- 

 fied (figures 1, 3, 8, and 13), or are more or less remotely sepa- 

 rated (fig. 4, Euchceta, and 5 and 9 b, Pontellce) . They are usually situ- 

 ated close to the cephalic ganglion, and look upward or partly forward. 



2. A pair constituting a prominence on the under side of the head 

 between the antennae* They have a single mass of pigment. The pro- 

 minence has a rounded or reniform contour in a vertical view, the latter 

 shape indicating the existence of two (or more) lenses, in many, if not 

 all cases, — a fact not distinctly made out by dissection. Figures 9 a 

 and 14 a, Plate 70 (Pontellce), represent this prominence in a lateral 

 view, of different sizes. Figures 9 b, 14 b, represent the same, as 

 appearing in a vertical view, visible through the head just behind, 

 or directly beneath the other eyes. In 9 b the reniform shape is dis- 

 tinct. Figures 4 and 5, are other examples. Figure 10 (Catopia) 

 represents a species, in which a spherical lens was very distinct, and 

 only one could be made out. Figure 2 is an upper view of the same, 

 in which view also only a single lens was distinguished. 



The pigment is either blue-black (like a piece of solid indigo), or 

 carmine. 



These eyes may be designated, for distinction, the latter, the infe- 

 rior eyes, and the former, the superior. 



* The author follows Edwards in considering these organs eyes, who states that he 

 dissected out the lenses and found that the eyes were compound. 



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