56 



At least with regard to the structure of the pupae we know, Splueronella ArgisscB, 

 Splicer, insignis and Choniostoma mirabile come rather close to the two preceding species ; 

 each of them will now be treated separately. 



Sphceronella Argissce. Of this species I have found a single female pupa (pi. IV 

 fig. 3 1 and fig. 3 m), which in the most important features agrees with the female pupa of 

 8. Giardii. The body is ovate, naked all over, "15 mm. in length, and, like the last-men- 

 tioned species, provided with the pouch-like processes, in which antennulae (a), antennae (c), 

 maxillulae (e) -maxillae (f) maxillipeds (g), trunk-legs and caudal stylets (p) are developed, and 

 all these processes show about the same relative size as the corresponding organs in the 

 females compared with each other; moreover, the mouth is distinct, and the mandibles are 

 also seen in fig. 3 1. The animal is attached by a very peculiar crooked funnel of conside- 

 rable size (s), which is of course made of a viscous substance, and its narrower, though 

 comparatively thick, base proceeds from the front. 



Sphceronella insignis. Of Diastylis cornufa Boeck a single pupa was found (pi. X, 

 fig. lh), 14 mm. in length and sub-globular in shape. The mouth is well developed, as in 

 an adult female; antennulse, maxillulse, maxillae and maxillipeds are seen as protruding naked 

 pouches of somewhat irregular shape ; in front of the mouth are found two rather large, odd, 

 connected areas, and close behind them a smaller spot on each side of the median line; in 

 front of, and in an oblique direction from, the maxillulse, there are several small areas, and 

 finally a large transverse area, expanded in the middle, which joins the bases of the maxilli- 

 peds. All these areas are naked, and more or less prominent compared with the surroun- 

 ding skin. Except these organs and areas and the surface between them, the whole ventral 

 surface of the pupa and its sides are covered with hairs of medium length; the back is 

 covered in the same way on its most anterior part and on its posterior half, whereas a broad, 

 transverse area extends over the larger part of its anterior half; this area is naked, and 

 closely covered all over with irregular projections of a comparatively rather considerable 

 size, the real shape of which can only be recognised when seen obliquely, whereas a perpen- 

 dicular view gives the impression that this surface is covered with numerous irregular lines, 

 forming ovals, oblong spots or simply flourishes. I have been unable to find out with 

 certainty the sex of this interesting pupa, as the adult male of this species is devoid of 

 trunk-legs; however, I consider it to be a female. 



Choniostoma mirabile. On the gills of a Hippolyte Gaimardii M.-Edw. I have 

 found a number af larvae, which showed all the stages transitional to that of the pupa, 

 besides numerous fully developed pupae (pi. XI, fig. 1 g — 1 k). A comparison between the 

 figures 1 h, 1 i og 1 k, which are drawn to the same scale of enlargement, will show that 

 the pupae differ much in size and somewhat in shape; the largest specimen I have measured 

 is "38 mm. broad and "27 mm. long, the smallest only *27 mm. broad and - 19 mm. long, 

 and one specimen, which was still enclosed in the skin of the larva, is only -19 mm. broad 

 and - 18 mm. long. So the pupce grow very considerably after breaking out of the larval 



