OCR Text |
Show 1896.] FROM THE SANDWICH ISLANDS. 207 There are no genital papillae. The first distinct septum separates segment iv. from v. This and the three following-in fact all the septa which lie in front of the gizzard-are strengthened not only by an increased thickness, but by muscular strands which bind septum to septum and to the body-wall. Following the gizzard are four thickened septa, of which the last bounds the thirteenth segment posteriorly; here also are a few muscular threads passing between the septa and from them to the body-walls. These threads are found as far back as the septum lying between xv. and xvi. As is so often the case, these bands arise from one segment and traverse another to be attached to the septum behind it or to the body-wall between. The direction of the muscular strands is outwards. Two particularly strong muscular bands-one on either side and latero-dorsal in position-attach the gizzard to the septum next following. The gizzard is round in form-neither particularly elongated nor bell-shaped. The intestine begins suddenly in the xvth segment; the ca3ca are simple and conical in form, extending through three segments. The last heart is in segment xiii. The large sperm-sacs are as usual in the xith and xiith segments. The spermiducal glands are large and loosish in texture, owing to their extensive lobulation. They extend through segments xvii. to xxi. inclusive. The duct is moderately long and bent into a curved horseshoe. The spermathecae are four pairs lying in segments vi.-ix.; the point itself is oval, with a tendency to be pointed at the tip ; the duct is short. The diverticulum is longer than the pouch and moniliform distally. There are egg-sacs in segments xiii.-xiv. Hab. Trinidad. § The Distribution of Perichaeta, Except for accidental transference to this country and to other temperate climates, the genus Perichaeta is purely tropical in its range, and is practically confined to the Oriental region and to the Neotropical; from the former it reaches the Australian part of the Eastern Archipelago and the continent of Australia itself. Africa has no true Perichaeta, except P. capensis, which is also Oriental. In all parts of the Oriental region Perichceta is a dominant form, and always constitutes a large proportion of the gatherings of worms from such localities. It is also exceedingly abundant in some of of the West Indian Islands, such as Trinidad, Bahamas, Grenada, Jamaica, Bermudas, and Barbados. It occurs more rarely upon the South American Continent. The following species are already known to occur in both the Old and the N e w "Worlds :-P. indica, P. sumatrana, P. houlleti, P. clyeri, and P. posthuma. Peculiar to the N e w World, so far as published records go, are P. sancfi jacobi, P. ringeana, P. elongata, P. pallida, P. bermudensis, P. barbadensis, |