Paekek. — Anatomy and Embryology of Scymnus lichia. 



233 



the posterior border of the pectoral : it receives the blood from both pectoral 

 and pelvic fins, but is without important feeders in the intermediate part 

 of its course ; and, lastly, it is fully established as a fairly early embryo of 

 Scymnus. All these facts tend to support the theory that the lateral vein 

 represents the veins of the primitive vertebrate lateral fins, and is therefore 

 a structure of considerable morphological interest. 



Fig. 1. 



Fig. 2. 

 Fig. 3. 



Fig. 4. 



Fig. 5. 

 Fig. 6. 



EXPLANATION OF PLATES XXXI. AND XXXII. 



Dissection of Scymnus lichia, female, made by opening the body-cavity by a 

 median ventral incision ; intended to show the general disposition and pro- 

 portion of the chief abdominal viscera (about A nat. size). 



Ir, the two lobes of the liver turned 



forwards to show the other viscera. 



o. gl, oviducal gland, shown in dotted 



outline through the liver. 

 pn, pancreas. 



py. st, pyloric portion of stomach. 

 spl, spleen. 

 2i. p, urinary papilla. 

 ut, uterus. 

 ut', cloacal aperture of uterus. 

 The stomach and intestine from the ventral aspect (f nat. size). 

 The stomach and intestine from the right side (§ nat. size). 



In fig. 2 the bursa Entiana is opened, as well as a portion of the intestine, so 

 as to show the pyloric and spiral valves. 



ab.p, abdominal pore. 

 b. e, bursa entiana. 

 cd. st, cardiac portion of stomach. 

 cl, cloaca. 



/. t, Fallopian tube. 

 /. t', common peritoneal aperture of Fal- 

 lopian tubes. 

 g. h. o, gastro-hepatic omentum. 

 int, intestine. 



a. in. a, anterior mesenteric artery. 



a. sp. v, anterior splenic vein. 



b. e, bursa Entiana. 

 b. d, bile duct. 



cd. st, cardiac portion of stomach. 



cor. a, coeliac artery. 



du. a, duodenal artery. 



du. v, duodenal vein. 



g. a, small left gastric artery. 



I. g. a, lieno-gastric artery. 



l.g. v, lieno-gastric vein. 



m. m. a, middle mesenteric artery. 



m. v, mesenteric vein. 



p. m. a, posterior mesenteric artery. 



pn, right, and|j;i', left lobe of pancreas 



p. v, portal vein. 



py, pylorus. 



py. st, pyloric portion of stomach. 



r, rectum. 



r. gl, rectal gland. 



spl, spleen. 



sp. v, spiral valve. 



w, wall of intestine. 

 Transverse vertical section through body-wall, a little anterior to pelvic fin (nat. 



size). 

 in, integument. m, body muscles. 



I. r, lateral ridge. p, peritoneum. 



l.v, lateral vein. 

 Transverse vertical section of an embryo in the third stage, taken along the line 



xy in fig. 13. 

 A similar section taken along x'y'. 



Both figures x 16. 

 an. d, archinephric or segmental duct. 



c, caudal vein. 

 cd, cardinal vein. 

 ch, notochord. 



d. ao, dorsal aorta. 

 g, genital ridge. 

 int, intestine with spiral valve. 



i. r, inter-renal body. 



k, tubules of kidney (metanephros) . 



l.v, lateral vein. 



my, spinal chord. 



visr, mesorectum. 



pv, pelvic fin. 



r. gl, rectal gland. 



