Decapoda — Macrura , A nornura. 
59 
The existing species are confined to the deep sea, and, like Table-case 
many other deep sea animals, are blind. Some, at least, are No - 11 ■ 
phosphorescent, and a living example of Polycheles phosphorus (of 
which a specimen is exhibited) (Fig. 38) was observed by Dr. Alcock 
to be “ luminous at two points 
between the last pair of thoracic 
legs where there is a triangular 
glandular patch.” A copy of a 
drawing made from a living speci- 
men of another species, Polycheles 
sculptus, dredged at a depth of 695 
fathoms in the Gulf of Panama, 
shows the red coloration that is very 
characteristic of deep-sea Crustacea. 
The fossil species are represented 
by a cast of Pry on arctiformis , from 
the Lithographic limestone (Jurassic) 
of Solenhofen in Bavaria. 
The members of the tribe Tha- 
lassinidea are burrowing forms, 
with a soft, loosely built body. They 
form, in some respects, a transition 
to the Anomura, in which, in some 
systems of classification, they are 
included. 
In the genus Callianassa , of 
which one species, G. subterranea, 
occurs on the south coast of England, 
one of the chelae of the first pair of 
legs is much larger than the other 
and is of peculiar form. A specimen 
of the large G. armata from the 
Fiji Islands is exhibited. 
Thalassina anomala is a widely 
distributed tropical species, especially 
characteristic of mangrove swamps, 
but sometimes found burrowing in 
able distance from the sea. 
Polycheles phosphorus, female. 
(After Alcock.) [Table-case 
No. 11.] 
damp earth at a consider- 
Sub-Order 2. — ANOMURA. 
The Anomura commonly have the abdomen more or less bent Table-case 
under the body, or else spirally coiled and asymmetrical. The No - 12, 
