CHAETODERMA MONTERE\'ENSIS. 61 



somewhat though ganghon cells are lacking. From each of these enlargements 

 a nerve is developed, and after branching in the pharyngeal musculature becomes 

 lost to view. This subradular system does not appear with the diagrammatic 

 clearness of the one in C. attenuata, but there is no especial difficulty in determin- 

 ing its relations which are essentially the same in the two species. 



In the posterior regions of the body the nervous system very closelj' resembles 

 that of C. attenuata. 



The gonad, with the usual characteristics and relations, opens into the for- 

 ward end of the pericardium by means of comparatively large tubes in sexuall>' 

 mature animals. In some animals, possil)ly owing to killing fluids, the peri- 

 cardial cavity is greatly distended with spermatozoa which have made their 

 waj' into the proximal half of the coelomoducts. These last named tubes com- 

 municate by wide ojienings with the jiericardium and on the other hand extend 

 forward as ciliated tubes for a short distance. Bej'ond this point their walls 

 become glandular and are thrown into numerous convolutions which render it 

 impossible, without nuich effort, to determine their exact relations. Posteriorly 

 each duct becomes more simple, though of fairly large calibre, so that it con- 

 tracts the cavity of the cloacal chamber; and on the ventral border of the fold 

 thus developed the outlet canal is formed (Plate 29, fig. 5). 



Chaetoderma montereyensis, sp. nov. 



This species is evidently abundant in the deeper waters of Monterey Bay, 

 California, as 155 were taken distributed through the following stations: nine 

 from 4485, seven from 4508, fifty-nine from 4522, fifteen from 4523, thirty-one 

 from 4524 and thirty-four from 4525. In every case the bottom was mud and 

 the depth varied from 39 to 35G fathoms. Chloretone (aceto-chloroform) was 

 used with good results as a narcotizing agent and 70 % alcohol served as a fixing 

 agent. The length of a medium sized specimen ' is 45 mm. with an average 

 diameter of 2 mm. through the prothorax and 3 mm. through the preabdomen. 

 The color in life and preserved material is yellowish white. 



The hypodermis very closely resembles that of C. attenuata. The spines 

 are represented in Plate 37, figs. 2, 3. 



The mouth opens through a slit in the subelliptical jjuccal plate (Plate 4, 

 fig. 17) and leads into a laterally compressed tube which becomes circular in 



• Generally speaking the larger specimens come from the shallower depths. This is very marked 

 in comparing those from Sta. 452.5 with others from Sta. 4508. These size differences, however, do not 

 appear to be correlated with any constant sfriiclural peculiarities. 



