178 BULLETIN OF THE 
thicker than those of the stomach. The intestine is short, slightly coiled, and 
opens externally through a dorsal anus. The “ventral gland” (vg), indicated 
by a depression in the external body wall on the ventral side of the anterior 
body region, has not yet appeared. 
The above larva is easily distinguished from the young Phyllochetopterus 
(Fig. 16) of about the same age, by the absence of dorsal median eye-spots near 
the long cilium on the preoral lobe of the head. 
In the next oldest larva (Fig. 5) of Telepsavus, we find that a new pair of 
lateral eye-spots has formed, and two slight projections, one on each side, at 
the base of the head, now appear. These last-formed bodies are the begin- 
nings of cephalic appendages, which later attain a great development. In other 
particulars, the two larve differ very slightly from each other. 
The next oldest larva (Figs. 8, 9) to that last described is one in which we 
have few changes, except those which result from the growth of the cephalic 
tentacles. Segmentation of the body has begun in the posterior hemisphere, 
but it has not yet appeared in the anterior. The present larva is almost iden- 
tical with one of those figured by Claparede and Metschnikoff.* 
A larva somewhat older (Figs. 10, 12) than that last mentioned shows more 
striking resemblances to other Annelid larve than any of those which have 
been spoken of above. Anterior and posterior portions share about equally in 
the elongation of the whole body. Very slight changes have taken place in the 
head, although the przoral lobe has elongated and become more prominent, 
and the median cilium has fallen off. 
On the ventral side of the body, a deep infolding (“ventral gland,” vg) 
of the body wall has taken place, at a point about one third the distance from 
the ciliated belt to the front edge of the lower lip. Eight simple lateral pro- 
tuberances, each bearing a small cluster of spines, are found in the interval 
between the cephalic appendages and the ring of cilia. On the fourth of these 
parapodia, counting from the anterior, there are spines (ms) which can be 
homologized with the cluster of spines on the fifth segment of Polydora.t These 
bodies occupy in Telepsavus nearly the same position as the crimson pigment 
spots (ms) near the “fourth segment” in Prionospio. The portion of the body 
behind the equatorial ciliated circle has become segmented. The segmentation 
constrictions are clearly defined, especially on the ventral side of the body. 
Two pairs of lateral branchie (b) appear on the segment just behind the ring 
of cilia, and a single pair on the following.t These appendages are richly 
ciliated over their whole surface. The cwsophagus (@) extends through the 
anterior part of the body cavity from the mouth to the seventh segment of the 
* Op. cit. 
+ In Polydora, according to A. Agassiz, these spines are found on the fifth seg- 
ment, which is really the fourth body segment if we regard the head as a single 
somite. The clusters of red pigment in Prionospio are also found on the fourth 
body segment. 
¢ In Dr. Wilson’s larva “two pairs of branchi# ” appear “on each of the two 
segments behind the thickened ciliated ring.” 
