MORPHOLOGY. 
Crust . 25 
addition to its ordinary albuminoids, contains amcebocites with a yellowish 
pigment, produced by a gland in the gill, traversed by oxygenated blood ; 
Cuenot. 
Bouvier (1) describes the vascular system of Portunus puber. For 
that of Palinurus vulgaris- and Platycarcinus pagurus, see Bouvier (2) ; 
and for that of the Crab, Bouvier (3, 4). The vascular system of Ma'ia , 
Grapsus , Stenorhyncus , &c., are treated of in Bouvier (5). 
Sense Organs. 
The abyssal Galathodea are mostly blind. The eyes have degenerated 
but are not reduced in size. A corneal surface is present, but no pig- 
ment. Blind species possess longer antennas. Henderson, p. 213. 
Certain deep-sea species are blind, while others, belonging to the same 
group at similar depths, see well. The latter have probably migrated 
into deep-sea water at an earlier period, and had no time to undergo modi- 
fication. Id. p. 214. 
The eyes of Serolidcc and Cymothoidce differ from the compound eyes 
of all other Crustaceans in the structure of the retinulse. The differentia- 
tion of the retinulaa of Serolis schythei into clear and pigment cells 
recalls the eyes of some Annelids and Molluscs. The eye is diplostichous. 
The views of Grenacher on this subject are probably more correct than 
those of Patten. Beddard. 
For the structure of the eyes of Ampeliscidce, see Della Yalle. 
Kingsley (3) deals with the development of the compouud eye of 
Crangon. 
Patten, in his “ Eyes of Arthropods,” deals chiefly with Insecta , but 
touches slightly on Crustacea. 
Respiratory Organs. 
- Faguridea found at a great depth ( e.g ., 2000 fath.) shew a modifica- 
tion of branchial leaflets, tending in the direction of the trichobranchiate 
type, with diminished respiratory surface. This fact, which is contrary 
to the general rule, seems to shew that the trichobranchiate form is 
ancestral, and that certain Paguridea are descendants of trichobranchiate 
Macrura. Henderson, p. 212. 
Nervous System. 
For the nervous system of Decapoda , see Bouvier (6). 
Petit describes the innervation of Grab’s claws. See Physiology. 
Digestive and Excretory Organs . 
Griffith finds that the Green glands of Astacus are truly renal, but 
that the so-called “ livers” of Crustacea are pancreatic. 
