4 

THE COMITY OF SPIDERS 

of doubt. J. E. Hull, for instance, contends that a number of J. 

Blackwall's species (of which the types are lost) should be reinstated 

(1920). Other arachnologists consider that the descriptions are 

inadequate to provide reasonable assurance of their identity and, by 

general consent, their claim to recognition has been discarded. 

A number of genera, notably those included in the Linyphiidae, are 

so badly defined as to be worthless. Changes there are sure to be, and 

in the meantime I follow several of the provisional conclusions 

reached by Dr. Jackson, who will, I hope, complete and publish his 

extensive researches into the natural groupings of Linyphiid species. 

A good example is provided by the species formerly included in the 

genus 

Diplocephalus

.

Dr. Jackson has pointed out that the sexual 

organs of these species clearly sort them into three divisions (1) 

becki

;

(2)

 fuscipes 

and 

castaneipes

;

(3)

 cristatus

,

 latifrons

,

 permixtus

,

adjacens

,

 jacksoni

,

 protuberans 

and 

picinus

.

F. P. Smith (1906) had 

previously reached the same conclusion. He referred 

becki 

to 

Tapinocyba

,

and 

fuscipes 

and 

castaneipes 

to a new genus 

Monocephalus

.

Later Simon correctly moved 

becki 

to 

Thyreosthenius 

but wrongly (a)

regarded 

castaneipes 

as a sub species of 

fuscipes 

and 

(b)

included this, together with 

latifrons

,

in 

Plaesiocraerus

,

of which 

the type is 

longicarpus

.

 Hull 

(1932) correctly adopts 

Monocephalus 

for 

fuscipes 

and 

castaneipes

,

but incorrectly adds 

becki 

and 

picinus

.

Becki 

is a 

Thyreosthenius

.

 Fuscipes 

and 

castaneipes 

are referable to 

Monocephalus

.

The remainder can be retained in 

Diplocephalus

,

with 

picinus 

linking this genus closely to 

Savignia

.

The status to be assigned to a genus cannot be defined with 

exactitude, but nevertheless I consider Simon is inconsistent when he 

splits up certain fairly compact genera, such as 

Bathyphantes 

and 

Meioneta 

(

Micryphantes

),

and merges such other well established 

genera as 

Singa

,

 Cercidia 

and 

Aranea

.

One of these genera, 

Meioneta

,

requires special attention.