NOTES AND MEMORANDA. 427 



the animal can be induced to protrude on irritation witli acetic acid, 

 and which it moves at short intervals in a longitudinal direction ; 

 examination by the aid of sections of the buccal region shows that this 

 organ belongs to the enteric tract, inasmuch as it is lodged in a 

 saccular fold of the cBSophagus ; no very definite account can be given 

 of its function, but it is presumed to secrete an offensive liquid ; the 

 walls of the intestine are remarkable for the presence of enormous 

 cells in the epithelium, very similar to those which are found in the 

 same region of some larval annelids. 



The perivisceral cavity is largely occupied by connective tissue, at 

 the expense of which it is probable that the generative elements are 

 produced. 



Segmental Organs. — All but the buccal segments are provided with 

 a pair of segmental organs ; those of the fifth segment are not, as are 

 the others, long and sinuous, but are shorter and broader, and are 

 evidently efferent ducts for the sexual products. 



Beproductive Organs. — The Sagitellidce are hermaphrodite ; in 

 mature specimens the whole of the coelom was observed to be filled 

 with ova and spermatozoa ; the former oblong, the latter with a 

 spherical head and a short tail. Passed out by the ducts of the fifth 

 segment, the ova appear to remain for a time in connection with their 

 parent, and under the protection of the elytra of the fourth and fifth 

 segments. They do not appear to undergo any metamorphosis, but 

 in the young the elytra form soft pads, and the lamellae of the hoods 

 are formed of separate cilia. 



Zoological Position. — Satisfied as to their belonging to the Annelida- 

 Chcetopoda, M. Uljanin proceeds to inquire whether they should bo 

 placed with the Oligochceta or Polychata ; the covering of the segments, 

 the absence of muscular bands in the coelom, the characters of the 

 segmental organs, are all points which distinguish them from the 

 latter ; the tentaculiform appendage of their buccal segment is not 

 found among the Oligochceta, while the presence of one or two pairs of 

 elytra on all the segments distinguishes them from both these groups ; 

 but these elytra are merely modified parapodia, and the characters of 

 the tentacular appendage are not suflicient to justify their separation 

 from the Oligochceta ; they must, nevertheless, form a distinct groui>, 

 for which a name is taken from the small annelid described byBuscb, 

 which seems to be a close ally of Sagitella — Tyj/hloscolex ; the chief 

 characters of the Typhloscolecidce, then, are these : — 



Body oblong, and consisting of a varying number of segments ; the 

 anterior or buccal segment is provided with one or more tentaculiform 

 appendages, and with cilia, or with lamellae formed of cilia ; all the 

 segments of the body carry one or two pairs of elytra. Some or all 

 (with the exception of the buccal segment) are armed on either side 

 with a few short spine-like setae. Pelagic. 



The two genera — Typhloscolex Busch (1851), and Sagitella 

 N. Wagner (1872) — are then defined, and of the three species of the 

 latter, *S^. Kowalewskii Wagner, and S. barhata and S. proecox, which 

 are new species, there follow short diagnoses : the animals have been 

 foimd at Trieste, in the Eed Sea, and in the Mediterranean. 



