appearance. Towards both sides of the ocular surface, towards the superior and inferior side, a change sets in as to the shape of the lenses, as best seen in horizontal sections (figs. 8, 10) they are lengthened and become more and more indistinct, and at last in the upper and lower marginal zones pass over into a reticulate, spongious mass, which seen in a longitudinal section presents almost the same aspect as in the regular prismatic surface of the eye. Fig. 11 _b_, _a_ being the visual field. It is, however, more densely reticulate, but a prismatic arrangement is quite as much evident as in the ocular surface proper. In the rule the passage from the prismatic surface to the reticulate is gradual, the prisms becoming by and by irregular in their outline and diminishing in size (fig. 12, _a_ the eye proper, _b_ the border zone), but there are also instances where the distinction between these two fields is sharp and without any gradual transition. In the inferior reticulate zone there are generally some oblongue, funnelshaped pits. I am uncertain whether they are to be regarded as regular parts of the eye structure or rather as burrows of some parasite. They do not continue deep down. If we now compare the reticulate zone of the eye with the maculæ of the hypostoma, for instance the vertical section fig. 16 with fig. 11 _b_, we find the most complete identity in structure. In the same manner the horizontal section of the border zone of the eye, fig. 8 _a_, fig. 10 _b_, and of the macula, fig. 17 are similar. The same chaotic, spongious mass in both, with some tendency to form prisms more evident in the longitudinal sections, where the same reticulate structure with predominant white, longitudinal streaks is so palpable. That there is a complete identity in structure between the two, the macula of the hypostoma and the border zones of the eye, is as evident as anything can be, but as to the functional identity or what this function may have been it is difficult to decide anything with certainty, at least it seems to me that the capacity of vision must in both have been far more restricted than in the eye proper. They rather give the impression as of rudimentary visual organs. =Asaphus raniceps= DALM. Pl. I f. 23-26.