. Enchytræidæ of the west coast of North America. Enchytraeidae; Annelida. ENCHYTR^ID^ 39 part about one-half the diameter of the atrium. Atrial glands sur- rounded by circular muscles at their entrance into the atrium ; all in the same, or in almost the same plane, so that a single horizontal sec- tion will cut them all at the same relative point. The narrow ducts of the atrial glands do not seem to enter the lumen of the atrium and penis, but continue down to the penial pore. Glands in the penial bulb large, and rarely more than four visible in the same section. MESENCHYTIL^US ORC^ sp. nov.
. Enchytræidæ of the west coast of North America. Enchytraeidae; Annelida. ENCHYTR^ID^ 39 part about one-half the diameter of the atrium. Atrial glands sur- rounded by circular muscles at their entrance into the atrium ; all in the same, or in almost the same plane, so that a single horizontal sec- tion will cut them all at the same relative point. The narrow ducts of the atrial glands do not seem to enter the lumen of the atrium and penis, but continue down to the penial pore. Glands in the penial bulb large, and rarely more than four visible in the same section. MESENCHYTIL^US ORC^ sp. nov. p1. XI, figs. I and 2 ; text-fig. Definition. — Length 6 mm,, width .5 mm 16. Somites 33. Pros- tomium large, round. Head-pore near apex. Intersegmental grooves deep on ventral side. Clitellum \ XI-XIII; clitellar cells unusually large. Body entirely transparent. 4> 4^ 4» 3i 3» 3i 3i 4. 4^ 3^ 4^ 4^ 3 Setae : laterals, 4, 4, 4, 3, 4, 4, 4, 3, 3; ventrals, 5, 6, 6, 7, 6, 6, 5, 3i 4? 5? 4- Sexual papillae. Fig. 16. Mesenchytrceus orcce. Si Si Si O' Ai 4i 4^ 4? Si Ai Ai 4i 4i 5i small. Septal glands in IV to VI. Brain longer than broad, posteriorly truncate, anteriorly deeply cleft. Dorsal vessel rises in XV. Intestine with a few chloragogen cells. Spermathecae unusually enlarged, consisting of an exceedingly long and slender duct with two minute globular diverticles at the center, and a long and thick terminal ampulla extending as far back as X ; no con- nection with the intestine. Funnels not above average size. Sperm- ducts about twice as long as the funnels. Penial bulb narrow, with- out any penial glands. A set of several large glands pierce the penial bulb and enter the lower part of the sperm-duct just above the pore. No accessory glands. Nephridia with several deep lobes. Lympho- cytes disc-like, not large. Color white, no pigment. Locality. — Orca, Alaska, June 25, 1899. Collected by Prof. Trevor Kincaid. Two specimens found under rocks on the seashore, above hi
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