226 



SCIENCE-GOSSIP. 



Fig. 7, C. nodatus.— Ventral 

 surface of male. 



family. The British Arrenuri at present known 

 only number about twenty, so a great many more 

 species will probably yet be found in this country as 

 the water-mites are more extensively investigated. 

 The next genus in point of numbers to Arrenurus 

 is that which forms 

 the subject of this 

 paper, namely, Cur- 

 vipes. Of this genus 

 there are about thirty 

 known species. Six- 

 3. \ teen of these are 

 figured and described 

 in Piersig's monograph 

 of German water- 

 mites, now being pub- 

 lished. The British 

 species number ten at 

 the time of writing, 

 nearly all of which 

 are now recorded for the first time in these 

 islands. Previous to Piersig's great work there 

 was rather a formidable list of specific names 

 under this genus ; but that author has done excel- 

 lent service by clearing a great number of them 

 away. I only hope that Piersig has not suppressed 

 too many. It is rather difficult to believe, on 

 looking at the figures given by 

 some writers of forms which 

 Piersig now says are identical, 

 that they can possibly be in- 

 tended to represent the same 

 species. Nevertheless, we can- 

 not do better than abide by 

 Piersig's ruling in the great 

 majority of cases. His draw- 

 ings are very beautiful and the 

 •details so well worked out that 

 I do not think anyone can fail to recognize what 

 he intends to represent. 



Previous to 1891 the genus Curvipes had been 

 known as Nesaea, a name introduced by Koch in 

 1842. In the first-mentioned year, however, 

 Koenike pointed out that the word Nesaea had 

 been appropriated by Lamarck in 1812 for a genus 

 of Polypes ; so he proposed the word Curvipes in 

 the place of Nesaea, and this has been accepted by 

 all the modern writers on water-mites. 



The Genus Curvipes. 

 The characters of this genus are : — Body soft- 

 skinned. All the legs supplied with swimming-hairs, 

 and all terminated by claws ; the tarsi and claws 

 •of the third pair of legs of the male are specially 

 modified. On each side of the genital fissure are 

 six or more so-called genital suckers or discs, 

 either on special plates or simply let. into the 

 skin. Epimera form two distinct groups on each 

 side. Palpi not chelate. Eyes wide apart. I will 







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tQ,oV°. 00 



Fig. 8, C. nodatus.— Genital area 



take as the type species of this genus Curvipes 

 nodatus Miiller. This is a large and beautiful mite. 

 It contains in a marked degree all the characters 

 common to this genus, and it is not uncommon. 



I. — Curvipes nodatus Miiller, 1781. 



Female. — I first describe the female, because I 

 think the females can be more readily recognised 

 than the males; in Arrenurus it is the reverse. 



The individuals of Curvipes nodatus vary much in 

 size, so also does the size of the body in- proportion 

 to the other parts. The mite from which I have 

 made my drawing ( J ) appears to be an average 

 specimen, so I will give its measurements. 



Body (fig. 1). — Oval or egg-shaped, the smaller 

 end being placed anteriorly. Length, 2 - 20 mm., 

 width about r6o mm. Colour: The front region 

 about the eyes, from where I have drawn a curved 

 line, is yellow (a, fig. 1) ; the body is red, rose- 

 madder being the nearest colour for comparison ; 

 sometimes there is another trace of yellow on the 

 posterior margin : the three patches on the front 

 part are of a very dark brown ; the two curved 

 pieces are a much darker red than the other part 

 of the body, and the T-shaped piece in the centre 

 of the back is a very light red. 



Eyes are exceedingly dark red, almost black. 



Legs vary in length in 

 different specimens in propor- 

 tion to size of the body. In 

 this particular mite the first 

 leg was 276 mm. long from 

 the epimera to the ungues. 

 Each leg, counting backwards, 

 gradually gets longer, until 

 the fourth leg measures 3^24 

 mm. The swimming-hairs on 

 the first leg are very few, but 

 the fourth leg has a great number (see fig. 2). 

 The first two joints of all the legs are generally a 

 bright yellow; the other joints are blue ; the two 

 colours blending gradually. Sometimes the tarsi 

 are also yellow. I have occasionally noticed 

 purple in place of the blue in the legs. 



Claws are not all alike on the four legs. The 



&& 



': 



Fig. 9, C. nodatus.— Last two joints of third pair of legs. 



first pair are represented in fig. 3, but the fourth 

 pair are as in fig. 4. 



Epimera are arranged in four groups (fig. 2), 



(!) All the drawings illustrating this article are bv Mr 

 Charles D. Soar, and from original material.— [Ed. S.-G.] 



