^'Corona analis" in Palpatores 21 



instance SUjlocellus (PI. I., fig. 1 o). we shall see clearly that the lateral pieces in the first- 

 named genera occupy the same position as the small tergite in Cyphophthalmi, the only 

 difference being that they do not meet in the middle line. We cannot therefore adopt any 

 other view than that the lateral pieces of "corona analis," in those Palpatores where such 

 an arrangement is found, represent the ninth tergite, of which the middle portion has remained 

 soft. This tergite is accordingly traceable only in Cyphophthalmi and in those Palpatores which 

 possess a "corona analis" fully or partially developed, but has altogether di.sappeared as a 

 chitinized piece in the other Palpatores and in all Laniatores. 



In Phalangioidte a fully developed " corona analis " proper is not met with, but in some 

 cases there are nevei-theless rudiments of it present. The least rudimentary " corona analis " is 

 found in Sclerosuina and allied genera, where Simon has already pointed out {b, p. 158) the 

 lateral pieces, and laid some stress on their presence as affording a character of his sub-family 

 Sclerosomatinre, which, however, in our opinion is not tenable with the restriction proposed by 

 him. But the median ventral piece is also present in these genera as a firmly chitinized, short 

 but proportionally broad plate, which is fully movably connected with the preceding seventh, 

 so-called fifth, sternite, and quite reaches the lateral pieces of "corona analis"; this small 

 median piece is, however, not visible unless operculum anale is lifted up. Gagrella Stol. and 

 allied genera are, in our opinion, nearly related to Sclerosoma and congeners, and in this 

 view we are confirmed by the fact that "corona analis" can be traced, though in a still 

 more rudimentary state, in at least some species of Gugrella. In G. minax Thor. (woodcuts 

 figs. C and D) the lateral pieces of " corona analis " are represented by a pair of very small 

 triangular pieces, and when operculum anale is lifted up, the median ventral piece is like- 

 wise to be seen in the shape of a very small plate, because it is firmly chitinized in this 

 species. The lateral pieces are traceable also in some other species of Gagrella, but we have 

 been unable to discern the median ventral piece in any of the other species in which we 

 have sought for it. — In all other genera of Phalangioidae both the lateral and the median 

 ventral pieces of "corona analis" have completely disappeared". As regards Isch i/ropsalis 

 and allied forms we shall speak below. 



We then come to the interpretation of the chitinous parts described and the general 

 question as to how many segments abdomen is composed of in Opiliones. 



Above we proved that in Cyphophthalmi the abdomen consists of nine complete segments 

 besides operculum anale; as to the latter we follow the interpretation of Thorell, considering 

 the operculum to be the dorsal part of a terminal segment, the ventral part of which has 

 disappeared. In Laniatores generally (Oncopodoida; excepted) we pointed out nine abdominal 

 sternites as in Cyphophthalmi, but besides operculum anale we were not able to discover more 

 than eight tergites ; nine sternites being present, the abdomen must in this sub-order be com- 

 posed of ten segments, but the ninth tergite has disappeared. In the two families of Palpatores 

 with " corona analis " well developed we find ten distinct segments. Above we proved that all 

 Palpatores have eight tergites and seven sternite.s, to which either operculum anale or a 

 " corona analis " must be added. In Nemastomatoidse and Troguloidse, the lateral pieces of 

 " corona analis " are the rudiments of the ninth tergite, the anterior ventral plate of " corona " 



' In order to avoid misunderstanding we may add that degrees, proceeding from the anterior to the posterior ex- 



■w-e do not mean to convey that those pieces have disappeared tremity of the body, so that the hindmost portion of the 



otherwise than as chitinized pieces, because during the de- body, which is not farther divided into segments, remains as 



velopment of the embryo, the segments are always formed by the anal segment. 



