...common characters of the Arachnida, however, help out our diagnosis in practice. They never possess more than four pairs of locomotive limbs, and the somites of the abdomen, even when the latter is well developed, are not provided with limbs. Again, in the higher Arachnida (Fig. 26),...

...considerable resemblance to some Crustaceans, the Arachnida — scorpions, mites, and ticks — never possess more than four pairs of locomotive limbs, and the somites of the abdomen are not provided with limbs. The Myriapoda, or centipedes, have more than twenty somites in their bodies,...

...respiratory organs, however, whenever these are differentiated, are never in the form of branchise as in the Crustacea, but are in the form either of...the head ; but in the former class, one of the two ANNULOSA: ARACHNIDA. normal pairs of antennas is never developed, and the eyes are always sessile ;...

...Clay (Eocene) is especially rich in the remains of Macrura and Brachyura. CHAPTER XXXV. ARACHNIDA. heart, when present, is always situated on the opposite...in the former class, one of the two normal pairs of antenme is never developed, and the eyes are always sessile ; while, in the higher Crustacea, the eyes...

...of branchiae, but of pulmonary vesicles, or ramified tubes or "trachea-, in which they breathe air; there are never more than four pairs of locomotive limbs, and the alxlominal sections never have limbs. The eyes arc always sessile, while in Ihc higher Crustacea they...

...of branchiae, but of .pulmonary vesicles, or ramified tubes or trachetE, in which they breathe air; there are never more than four pairs of locomotive limbs, and the abdominal sections never have limbs. The eyes nre always sessile, while in the higher Crustacea they...

...of branchiœ, but of pulmonary vesicles, or ramified tubes or trachcie, in which they breathe air; there are never more than four pairs of locomotive limbs, and the abdominal sections never have limbs. The eyes are always sessile, while in the higher Crustacea they...