226 PLEUROBRANCH MA. 
slender, usually curled, truncate, about equal in length to half the 
breadth of the body; it is a tubular organ, with a slit along the 
lower side, formed by the rolling up of a long, thin, membranous 
process. At the posterior edge. of the tubercle there is a shorter, 
flat pointed process, connected with the female organs. Color of 
dorsal surface yellowish-brown, lighter or darker and reticulated with 
dark brown, often specked with flake-white ; gill and proboscis dark 
purplish-brown ; the proboscis with a darker dorsal patch ; tentacles 
sometimes crossed by dark brown bands. Foot salmon-color. 
Odontophore very large and broad, with 150 to 170 rows of teeth; 
no median teeth ; all the teeth are similar in structure, and show 
only a gradual change in form and size from the inner to the outer 
ones. ‘The inner ones are elongated, slightly curved, narrow-lanceo- 
late, with a very acute point and with a smaller, narrow, sharp den- 
ticle on the inner edge, parallel to but shorter than the main point ; 
the outer teeth gradually become shorter, blunter, with a smaller 
denticle, which finally nearly disappears. Length, usually 30 to 
40; breadth, 10 to 14 mill. (V.). 
In the best preserved specimens the reproductive organs are often 
protruded, the forms of the different organs varying with the state 
of extension. The verge or most anterior organ, when fully 
extended, is long, cylindrical or a little clavate, with rows of minute 
recurved hooks near the end, and terminated by a slender curved 
spicule. The most posterior opening (urinal) is just at the anterior 
base of the gill, in the form of a small papilla, with a central open- 
ing. Between these there are two organs, on a more or less swollen 
common base; the more anterior is a large opening with raised mar- 
gin; a little behind and below this is a long, exsert, flat, usually 
tapered and acute, copulatory organ, varying much in size and form 
according to the state of extension. All these organs can be so re- 
tracted as not to be noticeable, but this seldom happens in alcoholic 
specimens, most of which show the organs more or less extended. 
The anal orifice is behind the base of the gill. (Verriil.). 
20 miles south of Block Island, in 38 fathoms; about 70 to 100 
miles south and southwest from Marthas Vineyard, in 28 to 310 
fathoms, both on bottoms of mud and of fine, compact sand, very 
abundant; Off Chesapeake Bay, in 31 to 300 fathoms; Off Delaware 
Bay, in 130 and 156 fathoms. 
With this species, and probably belonging to it, we often took 
gelatinous, but rather firm, cylindrical egg-clusters, about 20 mill. 
