January, 1903. 



KNOWLEDGE 



15 



Ascorhynchus which Hoek describes, the claw on these 

 first legs is either very small or " extremely minute." 

 For introducing these confusing links and gradations into 

 our genera we do not pretend to praise nature. We are 

 only describing it. But there is another perplexing cir- 

 cumstance. In the Ascoi'hynchns abyssi of Sars, and the 

 nearly related if not identical A. tridens of Meinert, the 

 unconscionable female, instead of having the egg-cells in 

 the fourth joint of the walking-legs, where by rule they 

 ought to be, has them in the second joint. Now here the 

 three species described by Hoek leave us in the lurch, for 

 of two of them only tlie males are known, and the third, 

 which he calls Ascorhynclius orthorhynchus, ought perhaps 

 to be transferred to a new genus, since the solitary female 



/ 



Ascorhjinchus tridens.-^^ic'meti. From Meinert. 



.specimen from New Guinea'will' not bend its proud pro- 

 boscis like the other species, and, on the other hand, it has 

 the fourth joint swollen in accord with custom. In thi.'^ 

 family Sars is disposed to believe that Alciiwus, Costa, 

 Parnzetes, Slater, and Nymphopaii;* Scliimkev^itsch, should 

 also be comprehended. Scxnrhynchus, Wilson, is identified 

 witli Ascorhynchus by Hoek. 



The remaining family is in some respects the most 

 eccentric and remarliable of all. The members of it, as 

 already exj)lained, have in the adult no chelifori, our last 

 pycuogouid family being so far in agreement, in rather 

 unfortunate agreement, with the families that were placed 

 first forming the section Achehita. But unlike the latter 

 they are fully provided with second and third appendages. 

 This family has been called Fasithoidte by Sars, on the 

 ground that Pasitlwe, Goodsir, 1842, though imperfectly 

 known, yet " from the perfect absence of chelifori and tlie 

 well-developed ])alpi" must be included in it. But 

 Goodsir's Piinilliiic may not impossibly be an Aiiimofhea, 

 as Dohru supposed, with the small chelifori overlooked. 

 In 1844, Goodsir mentions a thin narrow projection arising 

 from the anterior edge of the first segment immediately 

 licfore the ocular tubercle, and continued beyond the 

 middle of the rostrum. That his orii;iual account of 

 Piixillnif needed revision is thereby made clear, and the 

 narmw ]>rojection may refer to the chelifori indistinctly 



■ An AiHtnilian j;onu«, Ni/mphopxift^ was foimtltvl h\ llaswcli in 

 1S85 {Pntc. Linn. Soc. N.S. 'jf^ale.i, Vol. I\ , pt. i). 



perceived. At both dates he plainly declares that the 

 palpi, or second appendages in his genus are eight-jointed. 

 But Sars defines the family as having the palpi ten- 

 jointed. The i^enus Eiuh'ii', Philippi, lS4:}, has two 



Pasithoe vesiculosa, Goodsir. From Goodsir. 



species, but their family affinities also are distractingly 

 vague. In common with Goodsir's Pagithoe vesiculosa 

 they are still awaiting re-discovery and re -description. 

 That happy events of this kind are not beyond the reach 

 of scientific expectation derives some waiTant from the 

 strange case of Bhynchothorax mediierraneus, O. G. Costa, 

 1861. The Italian zoologist endowed this little creature 

 with one feature so unexampled in the tribe that among 

 the best judges of probability it was frankly disbelieved. 

 He attriljuted to it a seven-jointed tail-piece. Even the 

 two-jointed tail which the accurate Kroyer described in 

 Eurycyde hUpida was illusory, the appearance of an 

 articulation depending only on a transverse series of 

 dorsal setie. At all events the specimens which Dr. 

 Dohrn identifies with Costa's Ehynchothora.v have the 

 a\)domen or tail simple, as it is in all other well-established 

 Pycnogonida. The first of these specimens which Dohrn 

 had the good luck to obtain from dredging at Naples he 

 had the ill luck to lose before he had examined it with 

 care. Every naturalist will sympathise with the pangs of 

 regret he must have suffered, till at a later period other 

 specimens from the same locality came to his relief. Dr. 

 Hoek says : " On comparing the figures of Costa with 

 those of Dohrn, one scarcely knows which is the more 

 striking, the differences or the resemblance ; nevertheless 

 Dohrn has identified his species with Costa's, allowing 

 himself to be guided above all by the general impression, 

 and therein, I believe, he has been well advised." In the 

 later and more trustworthy description, no less than in 

 the earlier, there are some highly peculiar features. The 

 front part of the proboscis is imperfectly developed. The 

 ocular eminence stretches forward in a thin process over 

 and beyond the centre of the proboscis. The second 

 appendages are eight-jointed, with ancliylosis of the first 

 and secoud, of the fourth and fiftli, and of the sixth and 

 seventh joints. The walking legs have no cement glands 

 in the fourth joint, which is their usual position, but only 

 in the third joint of a sin^de pair, the last but one. The 

 cceeal prolongations of the intestine carry their gland-cells 

 no further than the first, or at most the third joint of 

 the legs, the continuation beyond this being limited to an 

 empty membrane. The ovaries are peculiar by want 

 of peculiarity, eccentric by being commonplace. For, 

 whereas it is the badge of all their tribe to develop ova 

 at least in some joint of the ambulatory limbs, this species 

 is so faithless to the traditions of its race as to have 

 ovaries not extending beyond the latei-.il processes of the 

 trunk segments. The genital openings are limited to the 

 last pair of legs as in Pyciiogoiiinn. We may either agree, 

 then, with Dr. Dohru that Rhynchothorax is the most 

 remarkable of all the Pycnogonida, or we may leave it to 



