DESCRIPTIONS OF GENERA AND SPECIES 647 



The internal anatomy of this genus does not show many differences from that of 

 the closely allied Fontoscolex; the characteristic calciferous glands of the latter are, 

 however, apparently missing; I stated that they were absent in T. hesperidumj 

 in the other species of the genus a microscopical examination has shown their 

 presence, but in an extremely reduced condition ; they are the smallest caeca, without 

 any folding of the lining membrane ; so small that in a dissection they would be 

 completely invisible; hence, no doubt, my statement that they were absent in 

 T. hesperiduTTi. The genus has, as all Geoscolicidae have, a gizzard. The nephridia 

 are paired, and the first pair are very much enlarged, as in Fontoscolex and other 

 genera. The last pair of hearts are in the eleventh segment. 



The reproductive organs are formed on a plan identical with that of other Geo- 

 scolicidae ; there is but a single pair of testes, in the eleventh segment ; opposite 

 to these is a large pair of funnels, which extend through at least two segments in 

 T. barbadensis; the sperm-sacs are a single pair in correspondence with the other 

 male genitalia ; they are peculiar in their extreme fineness, being at their commence- 

 ment the merest threads ; further back the calibre increases somewhat ; but they 

 are nowhere at all comparable to the sperm-sacs of other earthworms in breadth ; 

 they are as long as in Fiachaeta, extending through forty or fifty segments; the 

 hinder half of the sperm-sacs is provided with short diverticula — a unique feature. 

 The spermathecae are three pairs^ and are, as in all Geoscolicidaej without diverticula ; 

 they lie in segments vi, vii, viii, or ix, x, xi, the variation in position being 

 paralleled by the two species of Fontoscolex, F. corethrurus and P. trinitatis; they 

 open on to the posterior boundary of the segment which contains them. 



(i) Trichochaeta hesperidum, Beddaed. 

 T. hesperidum, Beddakd, Q. J. M. S., vol. xxxiv, 1893, p. 252. 



Definition. Moderately large worms. Setae irregular from the first setigerous segment, the 



ventralmost seta, however, maintaining its position throughout. Sperm-duct pores on XXIV. 



Spermathecae in VI, VII, VIII. Six moderately thick septa behind gizzard. Hah. — 



Jamaica; Trinidad. 



This species is to be distinguished from the next by the irregular setae and by 



its greater size. 



(2) Trichochaeta barbadensis, Beddakd. 

 T. barbadensis, Beddakd, P. Z. S., 1892, p. 701. 

 Definition. Length, 34 mm.; number of segments, 84. Setae paired. Clitellum complete. 



