290 ANDREWS. [Vol. V. 



cleared in glycerine, show rounded lenses or cones, and conical, 

 pigmented central parts, much more numerous in the latter 

 species than in the former, and also unusual in having the pig- 

 ment blue-black. 



Dasychone conspersa has numerous eye-like, branchial specks, 

 while in Hypsicomus circumspiciens there are paired eyes, the 

 long axes of which point, as I may say, away from some imag- 

 inary point at the centre of the whole branchial system. Each 

 eye has one conical, refractive body, somewhat projecting above 

 the general surface and enveloped in pigment, especially at its 

 inner apical end. 



At the tip of the branchia in Filigrana Huxleyi there is a 

 peculiar organ, intermediate, it seems to me, between that shown 

 in figures of Salmacina incrustans, Clap., by Langerhans (16), or 

 the presumably similar eye-like spots of 5. cedificatrix of Clapa- 

 rede's Supplement (4), on the one hand, and the more complex 

 structure already noted in Filigrana (Protula) Dysteri, Huxley, 

 as given by Claparede in (3),* on the other hand. 



Ehlers describes these organs as club-shaped collections of 

 modified epithelial cells surrounding a cavity. These cells are 

 club-shaped, the large ends at the surface, and appear to be 

 gland cells, as the peripheral part is sometimes full of granula- 

 tions. Irregularly scattered over the surface of the organ, and 

 far apart, are stiff, straight, hair-like structures, thought to 

 belong to small cells indicated by nuclei between the above 

 large, club-shaped cells. 



The author has found Nauplii enclosed in the branchial fila- 

 ments, and thinks these terminal organs may prove to be sen- 

 sory and at the same time secretory, discharging an adhesive 

 substance reflexly to catch prey. He recognizes their resem- 

 blance to the terminal eyes of Branchiomma, with which they 

 might prove to be homologous, assuming a change of function. 



A somewhat similar organ is found as a quadrangular area on 

 each ventro-lateral face of the buccal somite in Placostegus in- 

 comptus. Each has very many conical, highly refracting bodies 

 buried with apices inward and rounded bases next the cuticle. 

 A cell nucleus is present for each of these bodies, apparently. 

 The entire animal is colorless, in preserved specimens ; yet in 

 P. tridentatus and P. tricuspidatus, Hansen (20) and Langerhans 

 (17) describe similar areas on the buccal somite having red pig- 



