342 PROCEEDINGS OF THE ACADEMY OF [1895. 



somewhat in form this species recalls the nematodes. It possesses a 

 greater number of somites than is usual in the genus, and reaches a 

 larger size than any other Fridericia yet found in this region. The 

 sides of the somites, and especially the whole surface of the prostom- 

 ium, are plentifully studded with little rounded glandular knobs. 



Fridericia agricola n. s. 



This species has a length of 20-25 mm., and the mature worm 

 65 somites. 



The setse are normally arranged in fascicles of four to the thirtieth 

 somite, posterior to which only two persist. Sometimes the number 

 is respectively five or three owing to the retention of one seta of the 

 larger outer pair for a greater length of time than its fellow. This 

 occurs most frequently in the ventral bundles, and in the outer half 

 of a bundle. The seta of the lateral bundles average about one- 

 tenth longer than those of the ventral. In normal bundles the seta? 

 of the inner pair have a length of nearly two-thirds the outer. 



The spermathecffi (Plate XIII, figs. 1, 2 and 3) are quite different 

 # from those of F. longa. The long, slender stalks are from six to seven 

 times the length of the sacculated portion, and the whole organ propor- 

 tionately much larger than in the other species herein described. 

 The enlarged portion consists of a central thick- walled cylindrical 

 region, capped by a thinner- walled, more or less conical piece, which 

 at its apex opens into the oesophageal lumen. A single pair of 

 accessory sacs arise opposite to each other from the base of the thick- 

 walled region. These are of sub-spherical or sometimes more or less 

 flattened shape, and when fully developed quite as large as the 

 primary sac. They open into the latter by constricted mouths, and 

 being thin- walled, have spacious cavities which are usually filled 

 with spermatozoa, a bunch of which is likewise to be frequently found 

 projecting into the lumen of the oesophagus. .No glands are present 

 at the mouth of the spermatheca. 



The salivary glands (Plate XIII, fig. 7) are conspicuous, and each is 

 divided into from five to seven slender tubular branches, which may 

 themselves be simple or provided with one or two lateral twigs. 

 The tubes are of very irregular diameter. 



The supra-oesophageal ganglion is as in the last species. 



The ante-septal portion of the nephridia is ovate; the post-septal 

 slender, with a dorsal lobe about equaling in size the ante-septal. 



