498 SUMMARY OF CURRENT RESEARCHES RELATING TO 



remarkable and as yet unknown cliaracters in their structure and 

 development. 



Oxycorynia, a new Synaseidian Genus.* — Dr. E. von DrascLe 

 describes a remarkable form of comijouud Ascidian (Oxycorynia 

 fascicularis) obtained from Hogolen, an island in the Caroline Archi- 

 pelago. The animals are arranged in heads presenting a general 

 resemblance to a iir-cone, and supported upon cylindrical stalks, 

 which, in the specimen described, are about 2h in. long and rather 

 more than ^ in. thick. The oval spikes, which are sometimes pointed 

 at the apex, attain a length of about IJ in. and a breadth of f in. 

 The colour of the badly preserved specimen is a dingy yellowish 

 green. The branchial aperture is surrounded by a stellate marking ; 

 and on each side of the endostyle two or three dark lines run down 

 from the branchial aperture ; dark pigment also appears round the 

 cloacal aperture. 



The individual animals are 10 mm. long, of which about 6 mm. 

 belong to the branchial sac. The latter is of an elongated form, 

 narrowed before and behind ; and its hinder part covers a good deal 

 of the intestine. At the foremost part of the animal is the simple 

 round cloacal orifice. The branchial aperture is placed in the anterior 

 third of the branchial sac ; it is comparatively large, and is surrounded 

 by a veiy delicate cylindrical membrane, often cleft into four parts. 

 Examined from within, the branchial aperture is seen to be surrounded 

 by a frill-like ring, which appears strongly coloured by pigment- 

 granules. Outside this there are eight tentacles, alternately large and 

 small. The short oesophagus leads into a small smooth stomach, the 

 intestine proceeding from which forms a loop to the left of the 

 CESophagus, and bends forward, passing into the rectum, which is 

 filled with fpBcal masses, and may be traced nearly to the cloacal 

 aperture. Within the loop of the intestine are placed the ovaries 

 and the racemose testes, which consist of about six follicles, each of 

 which opens by a small duct into the common vas deferens, which is 

 traceable along the rectum. Posteriorly each individual animal has 

 a filiform appendage, which passes into the common peduncle, in 

 which it may be traced to a long distance by transverse sections. 

 This appendage is divided by a septum into two parts. The pe- 

 duncle itself consists of a dense tunic mass, in which the well known 

 large vesicular cells with parietal nuclei arc present in great quantity. 

 The individual animals are united by an extremely delicate colour- 

 less tunic. The individuals seated upon the margin of the peduncle 

 are short-stalked, and their stalks gradually increase in length towards 

 the middle, thus producing the spike-like form of the colony. 



The caudate lai-vee lie partly in the branchial cavity itself, partly 

 in diverticula of the body-wall. The embryo is characterized by a 

 peculiarly formed appendage, which bears five adhesive glands. All 

 the embryos observed showed indications of branchial hoops. 



At the summit of the common peduncle, where the appendages of 



* Veihandl. Zool. Bot. Gesell. Wien, xxxii. (1882) pp. 175-7 (1 pi.). See 

 Ann. and Mag. Nat. Hiaf., xi. (188B) pp. 455-7. 



