A Monograph on the Sub-class Cirripedia · Charles Darwin
CRYPTOPHIALUS MINUTUS.
Fig. 1, Cryptophialus minutus (female with an attached male) viewed laterally, but with the disc (H) rather turned towards the beholder, much enlarged; _a_, orifice leading into the sack; H, thin horny disc by which the animal is attached within its cavity; H′, upper free worn edge of the disc; _z_, male attached in its usual position to the edge of the disc of the female. 2, Cryptophialus minutus, natural size, within a half-inch circle; this represents the largest specimen which I have ever seen. 3, Half the orifice, with a large portion of the external membrane and of the membrane lining the sack. _a_, _a_, dentated horny rim of orifice. _b_, _b_, external membrane, with the underlying corium or true skin removed. _b′_, a horny bar, expanding at its lower end into a toothed plate, and at the upper end connected with the horny rim round the orifice. _c_, _c_, membrane lining the sack. _c′_, horny bar by which this membrane is strengthened. _c′′_, thickened membrane, or bar, expanding into fibrous sheets for the attachment of a muscle. _d_, delicate lateral lip, within the outer dentated horny rim. 4, Orifice of sack, cut off, widely open, viewed from above; _a_, horny dentated rim; _b′_, top of horny bar, where united to the rim; _d_, inner lateral lip folded backward; _d′_, lip, with coarser hairs, at the carinal end of the orifice.
5, Animal with the outer tunics removed, viewed laterally. _a_, dentated horny rim of orifice, continuous with _b_, outer membrane, here cut off. _c_, inner membrane of sack, continuous with _c_, _c_, the reflexed membrane of the body, by which the body is united to the disc and outer envelopes. _e_, lancet-shaped labrum. _e′_, projection behind the labrum. _f_, palpi. _g_, outer maxillæ, between which and the palpi lie the inner maxillæ and mandibles; these latter are rather exaggerated in size. _h_, first maxilliped, in a rudimentary condition, close above which is the articulation separating the whole mouth (_o_) from the first (^1) segment of the body. _i_, _k_, tapering appendages springing from the second and third segments of the body. _l_, pedicels of the three pairs of abdominal cirri. _m_, cirri, three pairs of. _o_, mouth, of great size, formed by the confluence of the lower segments of the gnathites. ^1, first segment of body, homologically the last or seventh cephalic segment. ^2, second segment of body, homologically the first thoracic segment. ^3, third segment of body, homologically the second thoracic segment. ^4, fourth segment of body, homologically the third thoracic segment. ^5, fifth segment of body, homologically the fourth thoracic segment. ^6, sixth segment of body, homologically the fifth thoracic segment. ^7, seventh segment of body, homologically the sixth thoracic segment. ^8, eighth segment of the body, homologically the seventh thoracic segment.
6, Front of mouth; _g_, outer maxillæ; _g′_, an articulation separating the mouth from the membrane of the first segment of the body; _h_, first pair of maxillipeds; whole figure on same scale with the labrum, fig. 9. 7, Maxillæ, drawn on thrice the scale as the outer maxillæ; _a_, apodeme. 8, Mandibles, drawn on thrice the scale as the outer maxillæ. 9, Labrum, on same scale with the outer maxillæ, fig. 6, and one third of the scale of the mandibles and inner maxillæ; _e_, labrum; _f_, palpi. _Genera_--CRYPTOPHIALUS AND PROTEOLEPAS.
Text from Project Gutenberg, public domain in the United States.