172 



the almost regularly oval transverse frame are fairly broad, and from the centre of the 

 lateral outline proceeds a very long solidly chitinised list (k') outward, and especially back- 

 ward, in an oblique direction; its proximal part is pretty broad, and its hindmost extremity 

 extends even a little beyond the posterior margin of the frame. Inside the acute angles 

 formed at the origin of the lists, and at the points where the curved lateral margins of the 

 frame meet the almost straight posterior margin, we perceive thick solid parts (k") which, 

 as lying beneath the skin, in this as in the following species are indicated by dotted lines, 

 and outside the frame by a light shade. In the soft membrane between the anterior part of 

 the frame and the rostrum appear two small, oval, tolerably solid chitinous rings (t) situated 

 rather far from each other, and each surrounding a very small area; obliquely in front of 

 them, and somewhat closer together, are two smaller and feebler, almost circular rings (u). 

 The antennulae (a) are short, with setae of nearly medium length, among which is a single 

 sensory seta (b). Antennas (c) of almost average length; they seem to be 3-jointed, having 

 an exceedingly short basal joint, whereas the two next joints are well developed, the termi- 

 nal seta being of the same length as, or longer than the last joint. Mouth-border of medium 

 breadth. Maxillae middle-sized; basal joint smooth. Maxillipeds (g) quite rudimentary 

 and difficult to detect, each consisting of two diminutive joints, the last of which is pointed. 

 The sub-median skeleton (h) forms on each side, obliquely inside and partly behind the 

 maxillae, a plate which is pierced with a hole and divided by incisions into irregular lobes. 

 The head is naked all over. The trunk is naked in the adults as well as in the above- 

 mentioned very young specimen; the latter has small trunk-legs, whereas I have not been 

 able to discover these appendages in the large specimens. The genital area (fig. 1 b) has 

 very oblique and anteriorly strongly converging lateral margins ; one of the receptacula seminis 

 (r) is represented in the drawing. 



MALE. Unknown. 



OVISACS. They are scarcely middle-sized (fig. 5 b and 5 c : fig. 5 a), sub-globular, 

 with slight difference in size where the contents are equally developed (while fig. 5 b com- 

 pared with fig. 5 c shows the usual difference of size between an ovisac containing eggs and 

 another with full-grown larvae). The longest diameter in the ovisac shown in the drawing 

 fig. 5b, is 1-8 mm. As many as twelve ovisacs may be found in one female. The eggs are 

 relatively extremely small and excessively numerous. 



LARVA. The specimen represented in fig. 1 e is '24 mm. long, but, as it was hinged 

 to a gill (by the adhesive plate s) in order to undergo its metamorphosis, the cephalothorax 

 is somewhat shorter and broader than in a specimen, which has not yet lunged itself (and 

 the third joint of the maxillae is bent forward); fig. If shows the front part of a larva pre- 

 pared out of an ovisac. As I have met with no larva about to swim out, or with one which 

 had just entered the branchial cavity of a new host, I am unable to determine the shape of 

 the cephalothorax in the free larva with absolute certainty, however, it seems to be some- 

 what broader than in any other of the larvae I have observed, and not much longer than 



