Tuhicoloiis Marine Worms, 29 



bent, sometimes nearly straight. It corresponds exactly with 

 the description of >S^. (Vermilia') serrula of Stimpson, from the 

 Bay of Fundy. It also corresponds with the S. triquetra of 

 Linnaeus and Fabricius, except in its smaller size, and more 

 delicate structure. In some specimens there is a structure 

 which, so far as I am aware, has not been noticed in either of 

 the above species. It consists of two lateral lobes, somewhat 

 more than one-twentieth of an inch in length, attached to the sides 

 of the anterior portion of the tube, and opening by narrow labiate 

 mouths on each side of the princijDal orifice, so that there ap- 

 pear to be three orifices close together, the central one round, 

 the lateral ones narrow and lunate. If the animal inhabiting 

 this shell has the structure of protula, one may suppose that 

 these lobes accommodate the lateral disk or expansion of the 

 thorax. As they appear only in certain specimens, they may 

 perhaps be connected with the function of reproduction, and be 

 of the nature of ovi-capsules, or they may serve to enable a 

 certain amount of respiration to proceed when the gills are 

 retracted. It would be interesting to study the living animal 

 with reference to these curious additions to its tube. 



Serpula vermicularis is one of the shells which I have described 

 in a former paper as found in the Pleistocene clay at Logan's Farm, 

 but I have not seen it from the Gulf, nor is it noted by Fabricius. 

 It is round, smooth, and tortuous. 



Genus Pectinaria. 



A shell, probably of this genus, made up of a single layer of 

 grains of sand, is frequent on sandy shores. It is perhaps P. 

 Groenlandica Grube, P. Belgica Lam., but I have not seen the 

 animal. 



The Serpula seminulum of Fabricius is a foraminiferous shelly 

 the 31iUolina seminulum described in my previous papers on 

 the Pleistocene deposits. The S. stellaris of Fabricius is the 

 Truncatulina lohaia, also a foraminiferous shell, parasitic on 

 shells and zoophytes, found in the Gulf of St. Lawrence and in 

 the Pleistocene beds. Serpula contortuplicata^ a common Atlantic 

 species, is also noted by Fabricius, but has not been found in the 

 Gulf. This industrious observer has also, under the genera Sahellaj 

 Nereis^ and Tuhularia, several species of tube-dwelling worms^ 

 which are perhaps identical with species of Sahella^ Amp)hitrite^ 

 &c., described by the naturalists of the "^"^nited States, but which 

 have not been observed in the Gulf of St. Lawrence. 



