44 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Mr. Wilson also states * tlie preliminary results of his investiga- 

 tions into the development of Diopatra cuprcea and Spioclioetopterus 

 oculatus. The egg-masses of the former are cylindrical, and are 

 18 inches to 2 feet long ; the larvfe are at first true Atrocha, with an 

 anterior apical tuft and two reddish eye-si3ecks ; they have a close 

 resemblance to the Eunicid larva figured by Claparede and Metschni- 

 kofi". The antennfe begin to appear when the larva has four setigerous 

 segments. The latter species has the larva mesotrochal, and very 

 similar to that of PhyllocJifetopterus (G. and M.) ; ten segments are 

 developed before the branchiae appear. 



Ocnerodrilus : a new Genus of Oligochgeta.t — Dr. G. Eisen gives 

 a description of a species of Californian Lumbriculid, for which he 

 forms a new genus, and to which he gives the specific name of occi- 

 dentalis, which is at once distinguished from all its allies by the fol- 

 lowing characters, some of which woixld appear to be of even more 

 than generic value. 



The efferent ducts are not free, but are partly grown together, and 

 there are no prostate glands ; the ducts and the receptacle open at the 

 same pore. There is no atrium, but there is a heart ; the dorsal 

 vessel is three-branched in front, but the ventral vessel is not forked. 



After giving in detail the generic characters of this and of the 

 other members of the family, the author raises, without settling, the 

 question whether the new genus should not be placed in a new family 

 or sub-family. As he justly observes, however, the characters of its 

 organization are, for the time, of far greater importance. 



The very muscular oesophagus extends through six segments, and 

 for the first five of them it is surrounded by a pair of very large 

 lobate glands, similar to but larger than those of Enchytrcetis. In the 

 seventh segment the oesophagus is provided with two large sac-like 

 appendages, of nearly the same structure as the oesophagus itself ; 

 these appear to be very characteristic. The " intestine proper," which 

 is very much less muscular than the preceding portion, is divisible 

 into two distinct parts ; the anterior portion, which is much the 

 broader, is covered with minute pigment-cells. The genus is further 

 remarkable for the distinct differentiation of two pairs of hearts, 

 situated in the eighth and ninth setigerous segments, and both com- 

 municating with the ventral vessel. What, however, is still more 

 characteristic is the forking of the dorsal vessel, which in all other 

 members of the family is " entire." Here, however, we find from the 

 seventh setigerous segment forwards two lateral branches, in ad- 

 dition to the main trunk ; these are connected one with another, and 

 with the ventral vessel. Gastric and perigastric vessels are also present. 



The segmental organs are found in all the setigerous segments 

 except the thirteenth and sixteenth ; in the former their place is taken 

 by the oviducts, and in the latter by the efferent ducts, and by the 

 receptaculum seminis. " The whole organ resembles more that of a 

 Limnodrilus or a Tuhifex, than those described as belonging to any 

 genus of the Lumbriculidse." 



* Zool. Anzeig., iii. (ISSO) pp. 455-6. 



t Nov. Act. R. Soc. Sci. Upsal., x. (1870) Art. IV., 12 pp. (2 pis.). 



