ZOROCRATES. 353 
We are thus compelled to choose between the probability of a convergence in general 
characters amongst members of originally widely divergent families, or the probability 
of a sporadic specialization of two appendages (possessed by all the members of the 
original phylum) cropping up here and there and themselves structurally converging 
towards a very similar type. 
Personally, I am of opinion that the probability lies with the second theory and 
that the evidence also tends strongly in this direction; and although it might be much 
more convenient, as in the first case, to place the “ Cribellates” together as distinct 
from the “ Ecribellates,” I cannot believe that this course furnishes as natural a 
classification as that represented in the second case. It seems more probable that the 
calamistrum and cribellum have been independently developed and specialized in 
different families than that members of groups ancestrally widely divergent should 
have converged and assumed general characters so similar as to be scarcely distinguish- 
able from each other. 
Fam. ZOROPSIDA. 
Cribellum and calamistrum present. Eyes 8, in two transverse, more or less parallel rows. Tarsal claws 2, 
with rudimentary third claw present. Tarsi and protarsi i. and ii. densely scopulate beneath, continued 
to form a false claw-tuft on each side, but without true claw-tuft. Tarsi iii. aud iv. densely scopulate 
on each side, but with a broad band of dense fine hair running through the centre. 
Tibie i. and ii. with 2—2—2—2—2 spines beneath (or sometimes 4 spines only on the outer side), the last pair 
apical, Calamistrum consisting of a small dense cluster of curving bristles, occupying, approximately, the 
second apical fifth of the inner side of protarsus iv. 
Spinners 6; posterior pair slightly longer than the anterior, terminating in a short conical second segment ; 
anterior pair shorter, larger, squarely truncate at the apex; median pair short and laterally compressed. 
The cribellum consists of a pair of oval-elongate, shallow, chitinized concavities, divided from each other 
by a narrow smooth septum. Mandibular teeth variable, three on upper margin and four on lower margin 
of fang-groove. 
Eyes in two rows, both slightly procurved ; eyes all subequal, centrals of posterior rows closer, three-fourths of 
a diameter apart, one and three quarters from the laterals. Eyes of anterior row equidistant; laterals 
three-fourths of a diameter apart. Palpal claw of female obsolete. 
ZOROCRATES. 
Lycodrassus, 1. Koch, Die Drassiden, Analytical Table, p. 2 (1866) *. 
Zorocrates, KE. Simon, Ann. Soc. Ent. Fr. 1888, p. 211. 
Satricum, O. P.-Cambridge, Biol. Centr.-Amer., Arachn. Aran. i. p. 99 (1892) +. 
* The generic name Lycodragsus was published in 1866, but without any typical species being referred to 
it, and it cannot therefore take precedence of Zorocrates. A spider labelled Lycodrussus robustus, L. Koch, 
from Cordova, Mexico, type, is contained in the Keyserling collection in the British Museum. Dr. L. Koch 
writes me that «‘ A detailed description of this species was priuted, but never published, and the specimen in 
the Keyserling collection is the type of this description.” The spider itself is one of the Cribellate forms. 
+ The name Satricum has been accidentally omitted by Simon in his Index to the Hist. Nat. Araign. éd. 2, i. 
p. 1081. 
BIOL. CENTR.-AMER., Arachn. Aran., Vol. II., March 1902. 22t 
