244 



at present to state, as they are both only known in the last larval stage. One 

 of the forms has already been recorded at an earlier date, whereas the other is 

 new. They are here simply designated as No. 1 and No. 2. 



Cryptoniseid No. 1. 



(PI. C, fig. 2). 

 Podascon (?) Stebbingi, Giavd & Bonnier. 



Characters. — Body comparatively robust, oblong oval in form, with the 

 greatest width rather behind the middle. Cephalic segment semilunar, with the 

 frontal edge evenly curved ; anal segment angularly produced behind. Eyes want- 

 ing. Basal expansion of antennulse short and broad, with the posterior edge 

 divided into 8 short, and somewhat irregular, blunt teeth. Antenna? rather 

 elongated, extending almost to the end of the 4th pedigerous segment, flagellum 

 fully as long as the peduncle. Coxal plates distinctly pectinate. Legs of the 

 usual structure, dactylus of the posterior pairs bidentate at the tip. Uropoda 

 with the outer ramus very small, scarcely exceeding half the length of the inner, 

 both having the extremity simple, and tipped with 3 slender bristles, the middle of 

 which it the longest. Colour not yet determined. Length of body 1.70 mm. Found 

 occasionally in the incubatory pouch of Onesimus plautus, Kroyer. 



Remarks. — This form is undoubtedly identical with the parasite recorded, 

 but without any name, by the Rev. Th. Stebbing in his account of the Amphi- 

 poda of the Barents Expedition, and for which MM. Giard and Bonnier have 

 proposed the name Podascon (?) Stebbingi. The specific name ought certainly to 

 be retained, as this form has been described and figured by that distinguished 

 author in a very recognizable manner; but, on the other hand, I regard it as 

 very questionable, whether it can be adduced to the genus Podascon of MM. Giard 

 and Bonnier, or even to the family Podasconidce of those authors. We do not 

 know the last larval stage of either of the 2 species of the genus Podascon recor- 

 ded, and of course are not in a position to institute any comparison. Indeed, 

 the only motive for referring the present annimal to that genus is based upon 

 the fact that it has been found on an Amphipod, belonging, however, to a ra- 

 ther different genus. But, in my opinion, this coincidence is far from giving full 

 evidence of its true relationship. Thus, as above stated, we find in the mar- 

 supial cavity of Mysidse 2 very different types of Epicaridse belonging to quite 

 different families, viz. a Dajid (Dajus) and a Cryptoniseid (Asconiscus), and 

 moreover, not seldom a Choniostomatid, Mysidion, belonging even to quite a 



