. A text-book of invertebrate morphology. Invertebrates. 600 INVERTEBRATE MORPHOLOGY. upon the inner surface of which there is on each side a collar- pore. The mouth (m) opens beneath the epistome into an oesoph- agus, -which in the collar region bears a dorsal diverticulum, the notochord {x), projecting forwards into the epistome. In this same region there is on each side a branchial slit {sp), structures which are apparently wanting in Rhahdopleura. Behind the oesophagus opens into a saclike stomach from. Fig. 273.—Diagrammatic LoNGiTUDiNAii Section through Oephalodiscus (after Ehlers from K
. A text-book of invertebrate morphology. Invertebrates. 600 INVERTEBRATE MORPHOLOGY. upon the inner surface of which there is on each side a collar- pore. The mouth (m) opens beneath the epistome into an oesoph- agus, -which in the collar region bears a dorsal diverticulum, the notochord {x), projecting forwards into the epistome. In this same region there is on each side a branchial slit {sp), structures which are apparently wanting in Rhahdopleura. Behind the oesophagus opens into a saclike stomach from. Fig. 273.—Diagrammatic LoNGiTUDiNAii Section through Oephalodiscus (after Ehlers from Korschelt and Heider). a = anus. n = nervous system. ex = excretory organ, sp = branchial slit. g = ovary. i = tentacles. m = mouth. x = notochord. which the intestine, bending upon itself, passes forwards to open (a) upon the dorsal surface of the visceral sac, a short distance behind the collar. The collar-pores probably serve as excretory organs, and it has been stated that the epistome-pores open into well- developed tubes (ex) terminating in the epistome cavity in a dilatation; they also have been regarded as excretory. The reproductive organs {g) are paired sacs, which open on the dorsal surface just in front of the anus. No circulatory system. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original McMurrich, J. Playfair (James Playfair), 1859-1939. New York, H. Holt and Company
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Keywords: ., bookcentury1800, bookdecade1890, bookpublishernewyo, bookyear1894
