Pecten \Pec"ten\, n. [L. pecten, -inis, a comb, a kind of shellfish. See Pectinate.]

1. (Anat.)
   (a) A vascular pigmented membrane projecting into the vitreous humor within the globe of the eye in birds, and in many reptiles and fishes; -- also called marsupium.
   (b) The pubic bone.

2. (Zo["o]l.) Any species of bivalve mollusks of the genus Pecten, and numerous allied genera (family Pectinid[ae]); a scallop. See Scallop.

3. (Zo["o]l.) The comb of a scorpion. See Comb, 4
   (b) .

Source: Webster's Revised Unabridged Dictionary (1913)
 

Marsupium \Mar*su"pi*um\, n.; pl. Marsupia. [L., a pouch], (Anat. & Zo["o]l.)
   (a) The pouch, formed by a fold of the skin of the abdomen, in which marsupials carry their young; also, a pouch for similar use in other animals, as certain Crustacea.
   (b) The pecten in the eye of birds and reptiles. See Pecten.

Source: Webster's Revised Unabridged Dictionary (1913)